CN111816039A - An electromechanical transmission control system and control method - Google Patents

Abstract

The invention discloses an electromechanical transmission control system and a control method, which relate to the technical field of mechanical automatic control. Servo motor movement; frequency conversion speed regulation circuit controls the speed of AC motor through the analog output signal of Beckhoff controller; Beckhoff controller circuit controls the logic control of servo drive and inverter through digital signal and analog signal; PLC control circuit controls The proximity switch on the door is used for safety protection, and is connected with the lead wire of the system power circuit breaker and the proximity sensor of the servo control circuit to form a loop. The invention adds PLC program so that the motor can realize the logic control and frequency conversion speed regulation system, draws the human-computer interaction interface, and provides the electrical wiring principle and control principle of the electrical control system, which enhances the practicability of the system.

Description

An electromechanical transmission control system and control method

technical field

The disclosure of the invention relates to the technical field of mechanical automatic control, in particular to an electromechanical transmission control system and a control method.

Background technique

At present, mechatronic engineering and mechanical manufacturing and its automation are industrial field applications of typical products such as motors, frequency converters, and servo systems.

Practical teaching is generally solved by the following methods: First, by purchasing products from relevant experimental teaching aid manufacturers, but the manufacturers and schools are out of touch with practical teaching. The second is through the method of virtual simulation. This method is generally combined with simple principle experiments and virtual simulation, which cannot achieve the purpose of exercising students' practical ability and improving their comprehensive quality.

The original experimental platform, first of all, is not very convenient for students to operate, and it will be a hindrance. Secondly, if you want to understand the wiring and control relationship of the entire equipment, you can only observe the rear of the equipment, but the wiring of some electrical components in the front will not be visible, which brings great benefits to the present invention in the actual course. trouble. In addition, the function is relatively fixed, and the operation is inflexible. If the present invention wants to add other electrical components, there will be no place to place them. It is impossible to wire and place electrical components independently, which lacks practicality.

Many technical processes and products in the field of electromechanical control demonstrate the ever-closer integration between mechanics and electronics and information processing. This integration is between components (hardware) and information-driven functions (software), resulting in an integrated system called an electromechanical system. The development of existing technologies involves finding the optimal balance between the basic mechanical structure, the realization of sensors and actuators, automatic digital information processing and overall control, and this synergy can lead to innovative solutions.

Therefore, mechatronics is an interdisciplinary field in which the following disciplines work together, mechanical systems (mechanical elements, machines, precision mechanics); electronic systems (microelectronics, power electronics, sensor and actuator technology); information technology (systems theory, control and automation, software engineering, artificial intelligence).

The development of the electromechanical control system is divided into four stages. At the beginning of the 20th century, mechatronics achieved control through only contactors and relays. In the 1930s, control systems evolved from intermittent to continuous control, increasing productivity. In the late 1950s, transistors and thyristors appeared, and thanks to the advantages of transistors and thyristors, a new era of electromechanical control systems had begun. With the development of digital and information technology, the control system has come to a new stage of computer numerical control. Since the 1970s, computer numerical control systems have been used in CNC machine tools and machining centers to increase the versatility and efficiency of machine tools and are widely used in production. With the birth of industrial robots, the present invention realizes a fully automated machining process. Today, with the continuous development of science and technology, the electromechanical control system is also developing in the direction of intelligence.

In view of the important role of curriculum experiment, its innovation has always been an important research and construction direction.

The experimental process of electromechanical drive control and the experimental equipment used are the key to supporting this course, and many universities and institutions have also carried out some research on the experimental platform accordingly.

Wang Rui from Xi'an University of Architecture and Technology has developed a PLC-based electromechanical-hydraulic integrated experimental platform measurement and control system. The platform controls the output torque of the electric motor through the direct torque of the frequency converter, and studies the parameter changes of the diesel engine and the electric motor during the power coupling output, which provides a certain reference for the follow-up research on the power output stability to a certain extent.

Besada Portas of Slovakia has developed a remote laboratory for the systems engineering and automation control course based on TwinCAT, the combined use of the laboratory Java server application and Easy Java Simulations (EJS). The TwinCAT system is used to close the control loop of the selected plant via the PLC in the PC.

The University of Maryland has established a mechatronics laboratory featuring an articulated robotic arm with industry-selective compliance with overhead machine vision for guidance and part inspection.

Programmable logic controllers (PLCs) are designed to replace the use of relay panels. PLCs overcome all the shortcomings of relay panels. Very efficient and reliable in applications involving sequential control and synchronization in the manufacturing, chemical and process industries. PLC is becoming more and more popular in industry due to its advantages of convenience, speed, reliability, system introduction and low cost. Currently, most of the controls used to execute system logic have been replaced by PLCs.

Dick Morley conceived the first programmable controller on January 1, 1968. His company, the Gould Modicon Company, developed the first PLCs, and the Model 084 PLCs were installed in the Oldsmobile division of General Motors and the Landis Company in Landis, Pennsylvania. The first PLCs were large and expensive. They only have on/off control, limiting their application to actions that require repetitive movements.

Through the above analysis, the existing problems and defects in the prior art are: (1) The original electric drive experimental platform and control equipment are inconvenient to operate, and the wiring and control relationship information of the entire equipment is not easy to obtain, and can only go to the rear of the equipment. Observe, but the wiring of some electrical components in front will be invisible again, which brings great trouble in practical application.

(2) The original electric drive experimental platform has relatively fixed functions and inflexible operation. If you want to add other electrical components, there will be no place to place them. The inability to wire and place electrical components independently, resulting in limited equipment practicability.

The significance of solving the above problems and defects is:

The invention takes the open electromechanical transmission control experimental platform as the object, firstly carries out the preliminary theoretical understanding and the layout of the electrical components through the existing electromechanical transmission control platform, and analyzes its power supply principle and control principle. Then use professional electrical drawing software such as EPLAN to draw the electrical schematic diagram, and then use the means of 3D simulation to design the electrical cabinet and simulate the position between the electrical components, so as to design a reasonable electrical cabinet layout. Then carry out the basic assembly of the electrical cabinet and the installation of various electrical components, including Beckhoff IPC, Siemens PLC, LS servo driver, LS inverter, motor, etc., and then perform the correct wiring according to the electrical wiring diagram. Finally, debug each component, and confirm whether it can be implemented through software programming.

SUMMARY OF THE INVENTION

In order to overcome the problems existing in the related art, the disclosed embodiments of the present invention provide an electromechanical transmission control system and a control method.

The technical solution is as follows: According to the first aspect of the disclosed embodiments of the present invention, an electromechanical transmission control method is provided, including:

Step 1, establish HMI human-computer interaction interface, and set motion parameters in AC motor motion control and servo motor motion control;

Step 2, link the variables in AC motor motion control and servo motor motion control;

Step 3, the PLC control circuit receives the variable of the motion control of the AC motor, judges whether the AC motor reaches the expected rotational speed through the frequency conversion speed regulation circuit, and controls the proximity switch on the door of the frequency conversion speed regulation circuit to regulate the movement speed of the AC motor;

The PLC control circuit receives the variables in the motion control of the servo motor, judges whether the servo motor moves according to the set value through the servo control circuit, and controls the proximity switch on the door of the servo control circuit to regulate the motion speed and position of the servo motor.

Preferably, after the third step, the oscillography is performed by monitoring the action, status and operation data of the system main circuit, servo control circuit, frequency conversion speed regulation circuit, Beckhoff controller circuit, and PLC control circuit by touching the screen.

Preferably, the AC motor motion control method includes:

Step 1, set the motion parameters of AC motor motion control: set the parameter of the inverter to 1, and run by the terminal; set the parameter of the inverter to 3, change the way of receiving signals, and perform analog input and voltage control ;

Step 2, link the variables of AC motor motion control, the variables include power frequency, induced electromotive force;

E为电动机的感应电动势。In step 3, the frequency conversion speed regulation circuit judges whether the AC motor reaches the expected speed, and controls the amplitude and frequency of the output voltage of the frequency converter through the acceleration and deceleration control mode, the V/f control mode and the pulse width modulation control mode, so that the

E is the induced electromotive force of the motor.

Preferably, the servo motor motion control method includes:

Step 1), establish the HMI human-computer interaction interface, set the servo parameters, input the current position of the Z axis: %.2f, the data type of %.2f is displayed as a floating-point data type, and only two decimal places are reserved;

Step 2) Set the associated variables to display the actual position of the X-axis; select the IP of the servo drive, and then display the current positions of the Z-axis and X-axis on the HMI; and enable the servo motor shaft through multiple button controls , jog, relative displacement and zero setting;

Step 3) Online monitoring is performed on the servo motor shaft to enable, rotate, move the large carriage, and stop the shaft;

Step 4) Perform oscillography, respectively connect the variables MAIN.AXIS1.NCTOPLC.ACTVELO and MAIN.AXIS1.NCTOPLC.ACTPOS, MAIN.AXIS2.NCTOPLC.ACTVELO and MAIN.AXIS2.NCTOPLC.ACTPOS to the actual speed and actual speed of the servo axis position control.

According to a second aspect of the disclosed embodiments of the present invention, an electromechanical transmission control system is provided, comprising:

In the main circuit of the system, connect the external power supply to the main power circuit breaker first, and then connect the system power circuit breaker and the servo power circuit breaker in parallel with the main power circuit breaker; the system power circuit breaker controls the on-off of the low-voltage circuit, and the servo power circuit breaker is formed. Control the on-off of high-voltage circuits;

Servo control circuit, using servo driver to control the motion of servo motor to control the movement of the large carriage and the middle carriage;

The frequency conversion speed regulation circuit adopts the frequency converter to regulate the speed, and controls the speed of the AC motor through the analog output signal of the Beckhoff controller circuit;

Beckhoff controller circuit controls the logic control of servo drives and frequency converters through digital signals and analog signals;

The PLC control circuit controls the proximity switch on the door of the servo control circuit and the frequency conversion speed control circuit for safety protection, and is connected with the lead wire of the system power circuit breaker, the servo control circuit, and the frequency conversion speed control circuit to form a loop.

Preferably, the system main circuit

Includes: Mains circuit breaker for system power supply;

The system power circuit breaker is used to control the power on and off of the PLC control circuit;

Servo power circuit breaker, used to control the power on and off of inverter, servo drive, servo motor and AC motor;

fuses to protect circuits;

Switching power supply, rectify AC 380V to DC 24V voltage.

Preferably, the servo control circuit includes:

Servo driver to control the motion of servo motor; after multiple servo drivers are connected from the servo power circuit breaker, connect multiple servo drivers in parallel with each other, and the network between multiple servos enables the network protocol to communicate with the Beckhoff controller circuit;

The encoder is used to encode the network protocol and the information for communication with the servo drive;

The proximity switch on the door is used for the safety protection of the servo motor; the proximity switch on the door is controlled by the proximity sensor, and the servo motor stops working when the door is opened.

Preferably, the frequency conversion speed regulation circuit includes:

Inverter, used to control the rotation speed of the AC motor; after the wiring is drawn out through the servo power circuit breaker, the two inverters are connected in parallel with each other, and the low-voltage control signal of the inverter is connected with the Beckhoff controller to control the running speed of the AC motor;

Beckhoff controller contacts for analog signal output of Beckhoff controllers;

Proximity switches on the two variable-frequency speed-regulating doors, which stop the AC motor from working when the door is opened;

The Beckhoff controller circuit includes: a coupler, an analog output module, a communication module, a digital input module, and a digital output module; the coupler is connected with the system power circuit breaker outgoing wiring; the analog output module, Data transmission and power supply are carried out between the communication module, digital input module and digital output module through the six contacts of E-BUS.

The electromechanical transmission control system further includes:

The touch screen is used to monitor the action, status and operation data of the system main circuit, servo control circuit, frequency conversion speed control circuit, Beckhoff controller circuit and PLC control circuit, and perform oscillography.

According to a third aspect of the disclosed embodiments of the present invention, a computer device is provided, the computer device includes a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the computer program causes the The processor performs the following steps:

Establish HMI human-computer interaction interface to set motion parameters in AC motor motion control and servo motor motion control;

Link variables in AC motor motion control and servo motor motion control;

The PLC control circuit receives the variable of the AC motor motion control, judges whether the AC motor reaches the expected speed through the frequency conversion speed regulation circuit, and controls the proximity switch on the door of the frequency conversion speed regulation circuit to regulate the movement speed of the AC motor;

The PLC control circuit receives the variable in the motion control of the servo motor, judges whether the servo motor moves according to the set value through the servo control circuit, and controls the proximity switch on the door of the servo control circuit to regulate the motion speed and position of the servo motor;

The oscillography is carried out by monitoring the action, status and operation data of the main circuit, servo control circuit, frequency conversion speed control circuit, Beckhoff controller circuit and PLC control circuit of the system by touching the screen.

The technical solutions provided by the embodiments disclosed in the present invention may include the following beneficial effects:

Based on the open design and manufacture of the original electromechanical transmission control experimental platform, the present invention conducts an in-depth analysis of the equipment on the original platform, and determines the relevant control flow and principle. Do theoretical analysis and design. According to the existing experimental platform, the present invention performs theoretical analysis and equipment principle analysis in the early stage. Identify the shortcomings of the original equipment. Use drawing software for redesign, including using Eplan to draw electrical schematics and design the appearance of an open experimental platform. In the present invention, testing experiments and programming are carried out, and the testing new platform can meet the expected requirements. Including the servo control of the axis can be completed, and the frequency converter can be used for frequency conversion speed regulation.

Compared with the prior art, the advantages of the present invention further include:

The present invention can well combine other knowledge learned in the past, and has strong openness, the content of the experiment can be close to the actual, and other electrical components can be added independently to realize other functions, and the coverage is very wide.

The invention makes the experiment more practical and can better reflect the process of combining theory with practice. The process of the experiment can be closer to the actual product installation and adjustment process, making the practice more practical and full of practicality.

The openness of the device of the invention is very strong, which can strengthen the students' hands-on ability, and at the same time, according to the experimental objectives, the selection of components, circuit design, installation and debugging can be carried out well, and hands-on wiring can also be performed. Conducive to deepening students' perceptual understanding.

The invention adds PLC program so that the motor can realize logic control and frequency conversion speed regulation system, draws the human-computer interaction interface, and provides the electrical wiring principle and control principle of the electrical control system, thereby enhancing the practicability of the system.

It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not limiting of the present disclosure.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description serve to explain the principles of the disclosure.

FIG. 1 is a schematic diagram of a three-phase winding provided by an embodiment of the present invention.

FIG. 2 is a schematic diagram of a three-phase symmetrical alternating current provided by an embodiment of the present invention.

FIG. 3 is a physical diagram of a servo motor provided by an embodiment of the present invention.

FIG. 4 is a working principle diagram of an encoder provided by an embodiment of the present invention.

FIG. 5 is a control block diagram of an LSLV-C100 provided by an embodiment of the present invention.

FIG. 6 is a linear diagram of acceleration and deceleration provided by an embodiment of the present invention.

FIG. 7 is a steady-state equivalent circuit of an asynchronous motor provided by an embodiment of the present invention.

Fig. 8(a) is a schematic diagram 1 of the LSLV-C100 inverter provided by the embodiment of the present invention; Fig. 8(b) is a schematic diagram 2 of the LSLV-C100 inverter provided by the embodiment of the present invention.

FIG. 9 is a main circuit diagram provided by an embodiment of the present invention.

FIG. 10 is a schematic diagram of a servo control circuit provided by an embodiment of the present invention.

FIG. 11 is a circuit diagram of a frequency conversion speed regulation provided by an embodiment of the present invention.

FIG. 12 is a circuit diagram of a frequency conversion speed regulation provided by an embodiment of the present invention.

FIG. 13 is a schematic diagram of a Siemens PLC control circuit provided by an embodiment of the present invention.

FIG. 14 is a three-dimensional model diagram provided by an embodiment of the present invention.

FIG. 15 is a working flowchart of an experimental platform provided by an embodiment of the present invention.

FIG. 16 is a flowchart of a logic control program provided by an embodiment of the present invention.

FIG. 17 is a control principle diagram provided by an embodiment of the present invention.

FIG. 18 is a schematic diagram of a current location provided by an embodiment of the present invention.

FIG. 19 is an online monitoring diagram provided by an embodiment of the present invention.

FIG. 20 is a monitoring diagram of an oscilloscope provided by an embodiment of the present invention.

FIG. 21 is 30 sets of positioning error diagrams provided by an embodiment of the present invention.

FIG. 22 is a linear fitting diagram of the Z-axis provided by an embodiment of the present invention.

FIG. 23 is a linear fitting diagram of the X-axis provided by an embodiment of the present invention.

Detailed ways

Exemplary embodiments will be described in detail herein, examples of which are illustrated in the accompanying drawings. Where the following description refers to the drawings, the same numerals in different drawings refer to the same or similar elements unless otherwise indicated. The implementations described in the illustrative examples below are not intended to represent all implementations consistent with this disclosure. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present disclosure as recited in the appended claims.

The present invention provides an electromechanical transmission control method, comprising:

Step 1, establish HMI human-computer interaction interface, and set motion parameters in AC motor motion control and servo motor motion control;

Step 2, link the variables in AC motor motion control and servo motor motion control;

Step 3, the PLC control circuit receives the variable of the motion control of the AC motor, judges whether the AC motor reaches the expected rotational speed through the frequency conversion speed regulation circuit, and controls the proximity switch on the door of the frequency conversion speed regulation circuit to regulate the movement speed of the AC motor;

The PLC control circuit receives the variables in the motion control of the servo motor, judges whether the servo motor moves according to the set value through the servo control circuit, and controls the proximity switch on the door of the servo control circuit to regulate the motion speed and position of the servo motor.

Preferably, after the third step, the oscillography is performed by monitoring the action, status and operation data of the system main circuit, servo control circuit, frequency conversion speed regulation circuit, Beckhoff controller circuit, and PLC control circuit by touching the screen.

In the present invention, the AC motor motion control method includes:

Step 1, set the motion parameters of AC motor motion control: set the parameter of the inverter to 1, and run by the terminal; set the parameter of the inverter to 3, change the way of receiving signals, and perform analog input and voltage control ;

Step 2, link the variables of AC motor motion control, the variables include power frequency, induced electromotive force;

E为电动机的感应电动势。In step 3, the frequency conversion speed regulation circuit judges whether the AC motor reaches the expected speed, and controls the amplitude and frequency of the output voltage of the inverter through the acceleration and deceleration control mode, the V/f control mode and the pulse width modulation control mode, so that the

E is the induced electromotive force of the motor.

In the present invention, the servo motor motion control method includes:

Step 1), establish the HMI human-computer interaction interface, set the servo parameters, input the current position of the Z axis: %.2f, the data type of %.2f is displayed as a floating-point data type, and only two decimal places are reserved;

Step 2) Set the associated variables to display the actual position of the X-axis; select the IP of the servo drive, and then display the current positions of the Z-axis and X-axis on the HMI; and enable the servo motor shaft through multiple button controls , jog, relative displacement and zero setting;

Step 3) Online monitoring is performed on the servo motor shaft to enable, rotate, move the large carriage, and stop the shaft;

Step 4) Perform oscillography, respectively connect the variables MAIN.AXIS1.NCTOPLC.ACTVELO and MAIN.AXIS1.NCTOPLC.ACTPOS, MAIN.AXIS2.NCTOPLC.ACTVELO and MAIN.AXIS2.NCTOPLC.ACTPOS to the actual speed and actual speed of the servo axis position control.

The present invention also provides an electromechanical transmission control system, comprising:

In the main circuit of the system, connect the external power supply to the main power circuit breaker first, and then connect the system power circuit breaker and the servo power circuit breaker in parallel with the main power circuit breaker; the system power circuit breaker controls the on-off of the low-voltage circuit, and the servo power circuit breaker is formed. Control the on-off of high-voltage circuits;

Servo control circuit, using servo driver to control the motion of servo motor to control the movement of the large carriage and the middle carriage;

The frequency conversion speed regulation circuit adopts the frequency converter to regulate the speed, and controls the speed of the AC motor through the analog output signal of the Beckhoff controller circuit;

Beckhoff controller circuit controls the logic control of servo drives and frequency converters through digital signals and analog signals;

The PLC control circuit controls the proximity switch on the door of the servo control circuit and the frequency conversion speed control circuit for safety protection, and is connected with the lead wire of the system power circuit breaker, the servo control circuit, and the frequency conversion speed control circuit to form a loop.

The system main circuit includes: a main power circuit breaker for supplying power to the system;

The system power circuit breaker is used to control the power on and off of the PLC control circuit;

Servo power circuit breaker, used to control the power on and off of inverter, servo drive, servo motor and AC motor;

fuses to protect circuits;

Switching power supply, rectify AC 380V to DC 24V voltage.

In the present invention, the servo control circuit includes:

Servo driver to control the motion of servo motor; after multiple servo drivers are connected from the servo power circuit breaker, connect multiple servo drivers in parallel with each other, and the network between multiple servos enables the network protocol to communicate with the Beckhoff controller circuit;

The encoder is used to encode the network protocol and the information for communication with the servo drive;

The proximity switch on the door is used for the safety protection of the servo motor; the proximity switch on the door is controlled by the proximity sensor, and the servo motor stops working when the door is opened.

Preferably, the frequency conversion speed regulation circuit includes:

Inverter, used to control the rotation speed of the AC motor; after the wiring is drawn out through the servo power circuit breaker, the two inverters are connected in parallel with each other, and the low-voltage control signal of the inverter is connected with the Beckhoff controller to control the running speed of the AC motor;

Beckhoff controller contacts for analog signal output of Beckhoff controllers;

Proximity switches on the two variable-frequency speed-regulating doors, which stop the AC motor from working when the door is opened;

The Beckhoff controller circuit includes: a coupler, an analog output module, a communication module, a digital input module, and a digital output module; the coupler is connected with the system power circuit breaker outgoing wiring; the analog output module, Data transmission and power supply are carried out between the communication module, digital input module and digital output module through the six contacts of E-BUS.

The electromechanical transmission control system further includes:

The touch screen is used to monitor the action, status and operation data of the system main circuit, servo control circuit, frequency conversion speed control circuit, Beckhoff controller circuit and PLC control circuit, and perform oscillography.

The present invention will be further described below in conjunction with hardware or related devices.

Selection of PLC:

Programmable controllers are not only easy to install, take up less space, consume less energy, and most have diagnostic indicators to help diagnose faults, but they can also be reused for other projects. Currently, there are more than a dozen manufacturers producing PLCs, such as: Siemens, ABB, Schneider, Mitsubishi, Omron, Bosch Rexroth, etc. Most of these companies make multiple models.

According to the requirements of this task, through the reasonable choice of performance and economy. The PLC used in the present invention is Siemens S7-200 PLC (DC/DC).

Comparison between PLC and other controllers:

(1) Comparison of PLC and relay control systems

In the long industrial process, the use of relays has been very extensive, but compared with PLC, due to physical properties, it is difficult to meet the needs of modern industrial control. Relay control is hard contact and hard wiring, which is easy to cause equipment damage. It is short-circuited, easy to wear, and has a short service life, while PLC is controlled by internal virtual contacts, so there is no physical loss. Other differences are shown in the table PLC and relay comparison.

Table PLC and relay comparison

(2) Comparison of PLC and SCM control system

In a broad sense, PLC is actually a set of single-chip microcomputers that have already been prepared. PLC and single-chip microcomputer are used in two intersecting fields. The background of PLC was to use single-chip microcomputer to find a controller that can often change the electrical diagram, and it has developed to today. , PLC has added a lot of functions, and these can not be realized by single chip. Table PLC and MCU comparison gives the comparison of PLC and MCU control functions and characteristics.

Comparison of table PLC and single chip microcomputer

(3) Comparison between PLC and computer control system

Modern computers have had high computing and data processing capabilities, and the computing speed has increased year by year, but many aspects of industrial control still lack PLC functions, as shown in the table PLC and PC comparison.

Table PLC vs PC

Fieldbus options:

Fieldbus technology is designed to define a serial communication network for connecting low-level equipment in a factory or processing plant, including sensors, actuators, single-variable controllers, and small (usually embedded) computers. The bit rate of the fieldbus is lower than that of a MAP or miniMAP network, but it functions to meet a range of requirements that are critical to the lowest level of automation control, including real-time response, low cost, safety, and power buses.

In 1984, ISO published a special standard, the International Standard Reference Model for Open Systems Interconnection. The purpose of this standard is to coordinate the interconnection of various computers, while allowing existing standards to be placed within the model, as shown in Table OSI Model.

Table OSI Model

Physical layer: involves the mechanical and (optical or) electrical devices required for data transmission. It is mainly responsible for transmitting bit information. Some communication systems, especially fieldbus systems, are very dependent on the functions contained in the physical layer.

Data Link Layer: is the most important layer in a fieldbus system, as this layer precisely defines the system functions related to real-time behavior, effective speed, etc.

Network layer: Provides all the means you need in an open communication system to route data from one application to the other.

Transport layer: optimizes the use of available network services to provide the required performance per session entity at the lowest cost.

Session Layer: Synchronizes data exchange between applications. Establish and disconnect sessions and define synchronization points.

Presentation layer: If a special syntax is used for data transfer, for example, the number of characters starting with a Pascal string, followed by the characters themselves, the application uses another syntax, such as a C string ending in a string. With special termination characters, the presentation layer is required for syntax conversion.

Application layer: Provides all necessary means for two applications to exchange information.

Choice of Beckhoff controllers:

The Ethernet high-speed transmission technology was introduced into the field of industrial control. This application promotes the combination of automation technology and Internet technology, which is the development trend of automation technology.

The Ethercat real-time Ethernet technology proposed by Beckhoff Company. Currently, it is widely used in industrial automation and motion control. With the rapid development of industrial automation, reliability, rapidity and stability have become an important field of industrial fieldbus control technology. However, industrial fieldbuses may not be sufficient for fast response times of less than 5ms. So some enterprises and organizations began to propose Ethernet-based solutions to meet the needs of practical applications.

Compared to other Ethernet-based automation solutions, Beckhoff's Ethercat offers the highest efficiency, the shortest cycle times, and the highest bandwidth usage. It is widely used in the automation management of industrial production. Excellent performance, flexible topology, and simple configuration functions. This sets new standards for reaching the limits of conventional fieldbus systems. 1,000 distributed I/Os can be allocated in 30 seconds, virtually unlimited network size and the best integration with Ethernet and Internet technologies. Ethercat allows replacing expensive star Ethernet topologies with simple line or tree structures. No need for expensive infrastructure components. All types of Ethernet devices can be integrated through switches or switch ports. The concrete realization process of the system is: install the control software with real-time processing capability on the operating system of the PC. After this work is done, the operating system of the PC becomes the real-time controller.

Beckhoff EtherCAT system composition and working principle

In some related applications involving electrical drives such as (coordinated) motion control, the performance of the fieldbus may be unsatisfactory (representing an apparent anomaly). The introduction of real-time Ethernet can overcome most of the above limitations, at least in principle. Real-time Ethernet is a high-speed communication system (100/1000Mbits/s) based on the well-known original Ethernet specification, designed for industrial applications to ensure very short transmission times and strict determinism for periodic traffic and timing.

An EtherCAT network consists of a master device and multiple slave devices. The master unit uses a highly compatible and standard Ethernet controller, and both computers equipped with the EtherCAT master network interface and embedded devices with Ethernet control can become masters. The TwinCAT software developed by Beckhoff is the main control software for the master station.

The operating principle of EtherCAT is as follows: the master station sends a data frame of up to 1486 bytes, the slave station can directly process the received message, and extract or insert the relevant data, and then the message processed by the previous slave station is transmitted to the next EtherCAT slave stand. The last EtherCAT slave station sends back the message processed by all the slave stations. After the master station receives the message, it analyzes and compares the message and sends it to the control unit.

Selection of controllers and input and output modules

Controller CX9020: The CX9020 is a compact, high-performance, efficient PLC and motion controller. In the field of Beckhoff control it is installed between the Bus Terminal controller series BX and the Embedded PC CX1000. Can run under Microsoft Windows CE operating system. In this way, it provides enough computing power to handle complex logic programs. The CX9020 does not require external storage media - the device boots the operating system from the internal flash memory. The heat dissipation of this module does not require a fan due to its low power consumption. The unit is a modular mechanical design. The basic configuration of this small unit is only 58x 100x 91mm.

EL1008, EL2008, EL4002 are digital input module, digital output module and analog output module respectively. There are eight channels for automation control, and the corresponding LED lights will light up when the channel is used. All three modules need to be powered by the e-bus system using a bus coupler.

EK1100 Coupler: EK1100 coupler for connecting EtherCAT to EtherCAT Terminals. The coupler is connected to the network via the Ethernet interface above.

The present invention will be further described below in conjunction with specific embodiments.

1) LS servo driver

Servo drives are controllers used to control servo motors. Its function is similar to that of a frequency converter. It is part of the servo system and is mainly used in high-precision positioning systems. Actuators are typically controlled in three ways: position, velocity and torque to precisely position the system.

Position control mode: take the position as the control target, accept the position control command sent by the host computer, drive the motor through the internal algorithm, and finally make the error between the given position and the feedback position 0, so as to realize the position following. Mainly used in printing machinery, CNC machine tools and other scenarios.

Torque control mode: take torque as the control target, accept the torque command sent by the host computer, and drive the motor through a certain algorithm internally, so that the error between the actual torque and the given torque is 0, so as to achieve torque control. Mainly used in winding and fiber pulling equipment.

Speed control mode: Take the speed as the control target, accept the speed control command sent by the host computer, usually an analog voltage, and drive the motor internally through a certain algorithm, so that the error between the feedback speed and the given speed is 0, so as to achieve speed control.

In this task, it is necessary to use Beckhoff controller to complete the motion control of two servo axes through EtherCAT network protocol, so the selected servo driver and the communication interface of the servo motor must be connected, so the servo driver used in the present invention is L7NA001B As shown in Figure 1. L7NA001B servo drive interface. The description of each interface is shown in Table 1:

Table 1 Servo driver interface description

The L7NA001B servo drive is compact in size and can be installed in a limited range. It needs to use a 3-phase AC200-230(V) 50~60Hz power supply connection, and the control power supply for controlling the servo motor is single-phase AC200-230(V) 50~ 60Hz, the internal interface has a built-in interface based on real-time Ethernet, which can communicate with other controllers or slaves with the same protocol. The connection method with the encoder includes single-turn absolute value of 19Bit and multi-turn absolute value of 16-bit (single-turn means that the current absolute angular position can be fed back at the moment of power-on, and multi-turn can also be fed back since it was nearly used when it was first used. how many turns). High response speed, up to 1kHz (when using a 19-bit single-turn absolute encoder). Support multiple control modes: cyclic synchronization (position, speed, torque) control mode, preset (position, speed, torque) control mode, homing mode, interpolation mode. The overall use is convenient, quick and easy to maintain, and the failure rate is low.

The invention simultaneously utilizes EtherCAT communication to connect the master server (controller) and the slave server.

2) Servo motor

The present invention uses two servo motors (model LS APM-SA01AMBN) and two AC motors, and the two motors have the same structure. The servo motor controls the movement of the large carriage and the middle carriage, and the AC motor acts on the main shaft and the drill floor respectively.

An AC servo motor is an AC motor that includes an encoder used in conjunction with a controller to provide closed-loop control and feedback. The motor can be placed with high precision and can also be precisely controlled according to application requirements.

AC servo motor is mainly composed of three parts: stator, rotor and encoder. The three-phase symmetrical current of the stator generates a rotating magnetic field of the stator, which will magnetize the rotor. When the rotor coil is magnetized by the rotating magnetic field of the stator, a three-phase induced electromotive force will be generated in the rotor coil, and the three-phase induced electromotive force The rotor magnetic field is then formed to drive the rotor to rotate (this is an asynchronous motor). When the rotor is a permanent magnet, it is a synchronous motor.

Rotating magnetic field: the current flows in from the tail end (X, Y, Z) and flows out from the head end (A, B, C) is positive; the axis of the three-phase winding is shown in Figure 1. Obviously, the A-axis, B-axis and C-axis form 120° in space.

The following three-phase symmetrical currents are passed through the above-mentioned three-phase symmetrical windings:

The variation curve of the three-phase symmetrical current with time is shown in Figure 2, the principle of three-phase symmetrical alternating current.

For a pair of two-pole motors, the maximum value of each phase current of the stator changes once with time, and the corresponding synthetic magnetic field rotates once. Considering that the current of each phase changes f ₁ times in one second, the speed of the rotating magnetic field of the two-pole motor is:

n ₁ =60f ₁ (r/min) (2)

周。考虑到每相电流一秒内变化f₁次，则相应的合成磁场一秒内将旋转

周，由此求得合成磁场的转速为：For a p-pole motor, the maximum value of each phase current of the stator changes once with time, then the corresponding resultant magnetic field will still move two pole pitches or

week. Considering that each phase current changes f ₁ times in one second, the corresponding synthetic magnetic field will rotate in one second

cycle, the rotational speed of the synthetic magnetic field is thus obtained as:

The stator is shown in Fig. 3 servo motor: it is composed of stator iron core and stator winding. The stator of the AC servo motor is a three-phase winding, and the windings are placed with a difference of 120°, and a rotating magnetic field is generated after the three-phase AC power is applied.

The rotor of the AC servo motor is a permanent magnet, and the rotor rotates synchronously under the influence of the rotating magnetic field generated by the stator.

Encoder (photoelectric sensor): The encoder is installed on the rotating shaft of the rotor. When the rotor rotates, the code disc of the encoder also rotates, and the output pulse of the encoder is fed back to the servo driver.

The structure of the encoder: encoder disc, light emitter, photoelectric receiver, amplifier circuit. The principle of the encoder code disc: the peripheral output is A-phase pulse, the middle output is B-phase pulse, and the innermost output is Z-phase pulse. The higher the accuracy of the encoder, the more space on its disk.

The working principle of the encoder is shown in Figure 4, including: the photoelectric receiver tube receives the signal from the outermost code disc, the photoelectric receiver tube receives the signal from the middle code disc, and the photoelectric receiver tube receives the innermost signal.

When the encoder rotates, the light emitted by the light transmitter shines on the photoelectric receiver through the code wheel. The photoelectric receiver converts the optical signal into an electrical signal, and sends it to the amplifier circuit to become a pulse signal, which is fed back to the servo driver to form a closed-loop system. A phase and B phase must have a certain phase difference.

3) LS inverter

Inverter is a kind of AC electric drive system, which is a power electronic conversion device suitable for AC motor speed regulation, which converts AC power frequency power supply into variable voltage and frequency. The working principle of the frequency converter is to change the torque and speed of the motor by changing the working power frequency of the motor. The object controlled by the inverter is an AC motor. The model used in the present invention is LSLV-C100.

The advantages of variable frequency speed regulation (compared with other AC motor speed regulation methods) The advantages of variable frequency speed regulation are: (1) stepless speed regulation, speed regulation accuracy; (2) smooth soft start to ensure motor safety; (3) in When the machine allows, the work efficiency can be improved by increasing the output frequency of the inverter; (4) It is very convenient to access the communication network control to realize production automation; (5) The forward and reverse directions of the motor do not need to be switched through the contactor.

The basic structure of the current mainstream frequency converters in the market includes:

Rectifier: Converts alternating current to direct current. Inverter: Converts direct current to alternating current.

Figure 5 is the control block diagram of LSLV-C100. include:

Acceleration and deceleration mode: During the process of load acceleration and deceleration, the curve of the change of the output frequency of the inverter with time is called the acceleration and deceleration mode. The general inverter has three linear modes (linear, nonlinear, S-curve), and the parameters can be set according to the characteristics of the load. For example: if the maximum frequency is set to 60Hz, the acceleration and deceleration time is set to 5 seconds. When the operating frequency is set to 30Hz, the time to reach 30Hz is 2.5 seconds, as shown in the linear graph of acceleration and deceleration as shown in Figure 6.

In the present invention, V/f control:

When the power frequency of the motor changes, the internal resistance of the motor also changes, which makes the excitation current of the motor change, which affects the output torque of the motor and the performance of the speed control system. The purpose of the pressure control method is to obtain the ideal torque-speed characteristic. In order to keep the excitation current unchanged, only the magnetic flux needs to remain unchanged during the speed regulation process. In order to achieve this purpose, the induced electromotive force must be changed while changing the frequency of the power supply, so that the ratio of frequency and voltage is a constant. And because the voltage drop consumed by the impedance of the motor stator is much smaller than the voltage on the stator, the induced electromotive force can be replaced by the power supply voltage.

In the equivalent circuit of the asynchronous motor (steady-state equivalent circuit) given in Figure 7, if the air-gap flux of the motor is represented by φ, it can be seen that the excitation current I _M , the induced potential E and the air-gap flux φ are as follows relation:

φ=MI _M (4)

Therefore, in order to keep the air-gap magnetic flux φ unchanged in the whole speed regulation process, it is only necessary to change the induced electromotive force E while changing the power frequency f, so that it satisfies:

In the actual speed control process of the motor, since E is the induced electromotive force of the motor, it cannot be detected and controlled directly, and other methods must be used to satisfy (6).

On the other hand, it can also be known from the equivalent circuit of Figure 7 that:

V=I ₁ Z ₁ +E (7)

in:

Z=j2πL ₁ +r ₁ (8)

is the stator impedance. Therefore, when the voltage drop across the stator impedance is small compared to the stator voltage, since V≈E, so long as the power supply voltage and frequency are controlled, (6) holds.

PWM: Pulse width modulation control, refers to the control method in which the inverter circuit part controls the amplitude and frequency of the output voltage (current) at the same time. The frequency converter used in the present invention is the LSLV-C100 frequency converter as shown in Figure 8 LSLV-C100 frequency converter.

Fig. 8(a) is a schematic diagram 1 of the LSLV-C100 inverter provided by the embodiment of the present invention; Fig. 8(b) is a schematic diagram 2 of the LSLV-C100 inverter provided by the embodiment of the present invention.

In Figure 8(a) and Figure 8(b), A-download interface, B-PNP/NPN selection switch, C-analog input V/I selection, D-panel control terminal, E-power terminal, F-ground terminal .

4) Weilun touch screen

By touching graphical buttons on the screen, the touch feedback system can operate various linked devices according to pre-programmed programs. Dynamic sound and video effects can be created using the display. As a modern computer input screen, the touch screen is currently the easiest, most comfortable and natural way of human-computer interaction. It can also be used to monitor the action, status, data, etc. of various equipment on the operating site. The objects to be monitored include PLCs, motors, frequency converters, some instruments and meters, etc. All automation equipment can be used as controlled objects to be monitored by the touch screen.

5) System electrical control part

The hardware circuit of the equipment includes the main circuit of the system, the servo control circuit, the frequency conversion speed control circuit, the Beckhoff controller circuit, and the Siemens S7-200PLC control circuit. The circuit drawing software used this time is EPLAN, which integrates electrical design, signal simulation, 3D control cabinet modeling, equipment selection, and supports a variety of electrical standards. Some special devices can quickly download the parameters and models of the required equipment from the network, which is very suitable for electrical design.

5.1) System main circuit

The main power supply of the system is 380V/50Hz, and the circuit diagram is shown in Figure 9.

The functions of each part in Figure 9 are as follows: F1: the main power circuit breaker, which plays the role of power supply for the system, F2: the system power circuit breaker, which controls the PLC on-off function, and F3: the servo power circuit breaker, which plays the role of controlling Inverter, servo driver, servo motor and AC motor on-off function, F4: fuse, protection circuit, V2: switching power supply rectifies AC 380V to DC 24V.

Connect the external power supply to the F1 main power circuit breaker first, and then connect the F2 system power circuit breaker and the F3 servo power circuit breaker in parallel with the F1 main power circuit breaker. Thus, F2 controls the on-off of the low-voltage 24V circuit, and F3 controls the on-off of the high-voltage 220V circuit.

5.2) Servo control circuit

Use the servo driver to control the movement of the servo motor to realize the controllable movement of the large carriage and the middle carriage, as shown in Figure 10.

The functions of each part in Figure 10 are as follows: SF1, SF2: LS servo driver, control the movement of the servo motor, M1, M2: Servo motor, BMQ1, BMQ2: Encoder, KM1: Proximity switch on the door, for safety Protective effects.

After the wiring is drawn from the F3 servo power circuit breaker, connect the two servo drives in parallel to each other to supply power. The network between the two servers uses the EtherCAT network protocol to communicate with the Beckhoff CX9020 controller. KMI and KM2 are controlled by proximity sensors, which can make the motor stop working when the door is opened.

5.3) Frequency conversion speed regulation circuit

Use the frequency converter to adjust the speed, and control the speed of the AC motor through the analog output signal of the Beckhoff controller, as shown in Figure 11.

The functions of each part in Figure 11 are as follows: LS1, LS2: LSLV-C100 inverter, control motor speed, M3, M4: AC motor, P1, AI1, RW1, ALM1, SA3.2, FW2, AI2, ALM2: all Contacts for Beckhoff controllers.

After the wiring is drawn out through the F3 servo power circuit breaker, the two inverters are connected in parallel with each other, and the low-voltage control signal is connected with the Beckhoff controller module to achieve the control function. The two KM1 switches have the same function as the KM1 switch in the servo control circuit.

5.4) Beckhoff controller circuit

The logic controller of servo and inverter is controlled by digital signal and analog signal, as shown in Figure 12.

The parts in Figure 12 are: A3: EK1100 coupler, A4: EL4002 analog output module, A5: communication module, A6: EL1008 digital input module, A7: EL2008 digital output module. After the wiring is drawn out through the F2 system power circuit breaker, it is connected with the EK1100 coupler of the Beckhoff controller, and other modules perform data transmission and power supply through the six contacts of E-BUS between the modules.

The PC is connected to the controller via an Ethernet cable.

5.5) Siemens S7-200PLC control circuit

Control the proximity switch on the door for safety protection, as shown in Figure 13.

After the wiring is drawn out through the system power circuit breaker of the main circuit of the system, it is connected with the Siemens PLC. The proximity sensor is connected to the terminals of the PLC to form a loop.

5.6) 3D model and physical map of the experimental platform

In order to improve the design efficiency of the experimental platform, the 3D model was drawn using EPLAN, as shown in Figure 14. The drawn model diagram is used for the layout and installation design of the electrical components in the early stage. Subsequent physical assembly will be based on the location of the components on this diagram as an important reference.

Table 2 Device Description

The present invention will be further described below in conjunction with the experimental platform program design.

1)TwinCAT software

TwinCAT is the abbreviation of "The Windows Control and Automation Technology", which is a control software based on PC platform and Windows operating system. Its function is to turn industrial PC or embedded PC into a powerful PLC or Motion Controller to control production equipment. The data exchange between PLC and field I/O is realized by "mapping" with field bus data area.

TwinCAT2 software includes TwinCAT System Manager and TwinCAT PLC Control. TwinCAT System Manager is mainly responsible for hardware configuration and I/O mapping, and TwinCAT PLC Control is mainly used for PLC program development and debugging. Multiple logic PLCs can be performed simultaneously on one PC, and each task runs independently without interfering with each other. It is a kind of soft PLC. It turns any compatible PC into a real-time controller. Based on this function, TwinCAT automation software and embedded PC are used as the control core of the system, and Beckhoff's self-developed perfect, efficient and mature function library is used to input and output the motion platform equipment, laser sensor, robot equipment and I/O. Coordinated control of equipment, etc. The EtherCAT master station is realized through TwinCAT software, and completes functions such as EtherCAT slave station device scanning, XML file parsing, and monitoring of the working status of all slave station devices. The function test software is used for the hardware function test and the whole machine performance test of the motion control system, which provides great convenience for hardware design improvement, software program debugging and motion control performance analysis.

2) TwinCAT parameter configuration

(2.1) Set the TwinCAT System Manager, click the SYSTEM-ConfigurationGeneral tab, and then click choose target. The Choose Target System window appears, displaying the controller's name CX-2DEAAB and IP address 5.45.234.171.1.1. Select it to connect.

When the selection is completed, the System Manager software will display the host name of the target controller and display whether the TwinCAT status of the target controller is successfully connected.

(2.1) After successfully connecting the target controller, click Set/Reset TwinCAT to config mode to switch the target controller to configuration. After the switch is successful, the software status bar displays: ConfigMode.

(2.3) Scan hardware devices. Right-click and select Scan Devices in I/O Device to perform automatic scanning.

Do it after confirming. After the scan is successful, expand the I/O Device tree structure. At the bottom, you can see all the selected I/O modules and devices. After term2 is opened, ports 1-8 will appear.

Click Set/Reset TwinCAT to run mode to complete the configuration and enter the running state, and the status display in the lower right corner will turn green. Finally, two axes are established in NC-Configuration and used in subsequent control.

3) Experiment platform control flow chart

Write the program according to the process shown in Figure 15. First, enable the axis to be powered on. At this time, the position of the servo axis will be displayed. If it is not 0, reset to zero. After that, set the position and speed of the axis movement. Start the motor until the motor stops rotating. At this time, the actual position of the current axis will be displayed. Compared with the set position, if it is the same, it will pass. If it is different, the motion control needs to be modified.

The present invention will be further described below in conjunction with experiments.

1) Use TwinCAT2 to make the AC motor realize logic control

(1.1) First open the TwinCAT PLC control software, click New in the File menu, and select the controller model that the program runs on. Here, select CX (ARM).

There are three ways to select Program Organization Unit (POU) type and language: Program, Function Block and Function. The following is an explanation of the language used:

ST (Structured Text): Consists of a series of instructions that can be executed as in a high-level language (IF..THEN..ELSE) or loop (WHILE..DO) statement.

LD (Ladder Diagram): A graphical programming language suitable for use as logic switches that can be used to set up different networks. A ladder diagram consists of a series of grids with current lines on the left and right sides of the network. Inside is a circuit diagram consisting of contacts and wires connected to the coil.

Here, select LD ladder diagram, and after selecting it, the programming interface will pop up.

(1.2) Program description: Complete the following tasks according to the requirements: when the start button is pressed, the spindle motor rotates immediately, and the background drill motor starts after a delay of 10 seconds. When the stop button is pressed, the bench drill motor stops immediately, and the spindle motor stops after a delay of 10 seconds. When the emergency stop is pressed, both motors stop immediately. Figure 16 shows the logic control program.

program:

0001 PROGRAM MAIN

0002 VAR

0003 TON1:TON; (*delayed on*)

0004 TON2:TON; (*delayed on*)

0005 X1 AT%I*: BOOL; (*start button*)

0006 X2 AT%I*: BOOL; (*stop button*)

0007 X3 AT%I*: BOOL; (*emergency stop*)

0008 Y1 AT%Q*: BOOL; (*spindle motor*)

0009 Y2 AT%Q*: BOOL; (*Drill floor motor*)

0010 A1 AT%I*: BOOL; (*Intermediate variable*)

0011 A2 AT%I*: BOOL; (*intermediate variable*)

0012 A3 AT%I*: BOOL; (*Intermediate variable*)

END_VAR

(1.3) At this time, you need to save the file, the file name is PLC. Compile after saving. The result of the compilation will be displayed in the information window, and 0errors means the compilation is successful. The PLC.TPY file will be generated in the target folder, which is needed when importing it into the SYSTEMMANAGER software.

Among them, .tpy is the associated file; .SDB is the binary system file; .SYM is the ASC code system file, which is often used in OPC communication.

(1.4) Link variables: Open the SYSTEM MANAGER software, right-click the PLC configuration, click Append PLCProject, select plc.tpy, and then click Open. Click Set/Reset TwinCAT to config mode to switch the controller to the configuration state. At this point, the set variable can be associated with the remote I/O point.

Click Term2 to expand the tree diagram, you can see the digital input ports 1 to 8, click on the corresponding ports and configure the variables. If the channel3 port is actually connected to the start button on the device, then connect Channel3 to the X1 variable, and the other interfaces are the same. Click Term3 to expand the tree diagram, you can see the digital output ports 1 to 8, click on the corresponding ports and configure the variables. If Channel4 is the forward rotation of the spindle motor, then connect Channel4 to the Y1 variable, and the other interfaces are the same.

At the same time, the Mappings under the IO configuration can see the establishment of the mapping, and there will be a program named "PLC" that successfully establishes a connection with the EL module hardware point. The ACTIVATE CONFIGURATION under ACTIONS is activated actively to make the previous configuration take effect. After activation, TWINCAT is restarted to run mode.

(1.5) Finally, log the program into the target controller, click ONLINE-login to download the program, and then click ONLINE-run to run the program.

(1.6) Press the start button at this time, and the equipment will start in sequence according to the logic instruction.

2) AC motor frequency conversion speed regulation control

The speed of the motor is controlled by changing the output of the analog voltage. The specific operation goes through the following steps:

(1) The model of the two motors selected this time is 51K180RA-SFW. The nameplate information is that the rated power is 180W, the rated voltage is 220V, the rated frequency is 50/Hz, and the speed is 1400RPM.

(2) According to the teaching requirements, when executing the logic program, the motor speed needs to be controlled at 1000RPM (spindle motor) and 800RPM (drill floor motor) respectively.

(3) By controlling the voltage signal of the EL4002 analog output module, the motor speed is controlled by the parameter setting of the inverter.

First of all, this is the control panel and key description of the inverter.

This is the alphabetical symbol table, shown in Table 3.

Table 3 Description

Parameter setting:

(1) Adjust the display of the inverter to drv, and then set its parameter to 1, which changes the drive mode and becomes driven by the terminals. When the multi-function input terminals P1 and P2 function as FX and RX functions, I The I17 and I18 of the /O group are set to 0 and 1 respectively. "FX" is the forward rotation command, and "RX" is the reverse rotation. Since the control signal of point P1 comes from the Channel4 channel of the EL2008 module (defined as the forward rotation of the motor in the Twincat variable), the motor can rotate forward when executed. Motor reverses when connected to Channel6. The settings for both inverters are the same. When the FX/RX terminals are ON or OFF at the same time, the motor stops running.

(2) Then adjust the display of the inverter to Frq, and set its parameter to 3, which changes the way of receiving signals, and becomes analog access, voltage control, and terminal AI setting (J1 is dialed to the V terminal) : 0-10[V], load 0~+10V signal between the inverter panel terminals AI and CM, as shown in Figure 17. The size of the AI controls the size of the frequency.

Port descriptions are shown in Table 4:

Table 4 Port Description

(3) Finally, run the logic program first, and then use the TwinCAT System Manager software for frequency conversion speed regulation. Input the set voltage into the output channel 1 of EL4002, the output state can be observed on output channel 1, the corresponding indicator light on the EL4002 will light up, and the set voltage can be measured by using a multimeter, thus realizing the variable frequency speed regulation. .

According to the maximum speed of the existing spindle motor is 1300RPM, the maximum analog voltage is set to 10V, so when you want to write a voltage of 7 or 8V in the SetValue Dialog, you can get the spindle speed of about 1000RPM. Similarly, in the port of the drill floor motor Write 6V voltage, you can get about 800RPM drill floor speed.

After adjusting the display of the inverter to rpm and then confirming, the current motor speed can be displayed.

3) TwinCAT control servo drive NC PTP

3.1) PC-based position control

TwinCAT NC PTP consists of axis positioning software, an integrated software PLC with NC interface, operating programs for commissioning and an I/O interface to the axes via various buses. TwinCAT NC PTP replaces conventional positioning modules and NC controllers.

The controller is modeled by exchanging data with drives and measurement systems via a fieldbus. Combining the processing power of the PC with the functionality of the PLC controls the movement of the axes. The PC has powerful computing power, and the use of a computer makes it possible to position dozens of axes simultaneously.

Features special logic functions including: linear coupling (electronic gearing), distance compensation, online master/slave and slave/slave conversion, flying saw (slash ju), cam control, external setpoint generator, multi-spindle coupling .

3.2) PLC programming to control the servo motor

First open the TwinCAT PLC control software, select the ARM core for the new program, and select the ST language format. Then, in the resource tab in the lower left corner, double-click the management library, then right-click the blank space and click Add Library to load a TCMC2.LIB library file, which contains the function texts that have been edited by Beckhoff required by the present invention.

Then switch back to the program editing interface. Define two variables of axis type, which are mainly used to display the position between NC and PLC, and some other structures are nested inside them. The variable of axis_ref is the variable of axis type. Enter a ";" in the program editing area.

0001 PROGRAM MAIN

0002 VAR

0003 axisA, axisB: axis_ref;

0004 END_VAR

After editing, "save as" and then "compile" to generate a TPY file (link variable). Next, link the NC and PLC variables, go back to the TwinCAT system manager software, right-click the PLC configuration, click Append PLC Project, and add the TPY file. Connect variables, connect MAIN.axisz.NCTOPLC, MAIN.axisz.PLCTONC, MAIN.axisx.NCTOPLC, MAIN.axisx.PLCTONC with the declared axis variables. PLC and NC transmit data through associated variables, the NC side will transmit the status, speed and position of the servo drive to the PLC, and the PLC will send the logic control program to the NC side.

After that, the HMI human-computer interaction interface is established. When running the program, the HMI can be used to control the action of the axis and the debugging of the axis more quickly and conveniently. Draw two function blocks in the HMI, double-click the function block to configure, and double-click the function block to fill in the parameter settings. : Enter the current position of the Z axis in Text Content: %.2f, %.2f represents the data type displayed as a floating point data type, and only two decimal places are reserved.

Set the associated variable in Textdisplay in Variables and fill in MAIN.axis1.NcToPlc.ActPos. The second function block is used to display the actual position of the X-axis. Select the IP of the controller, and then Login (program login and upload). After the program is logged in, run the program to see that the current positions of the Z-axis and X-axis are displayed on the HMI, as shown in Figure 18.

Eight button controls are added to the HMI for enabling, jogging, relative displacement and zeroing of the axis.

Finally, compile the program, log in and run, press the Z-axis enable button to enable the axis, and then press Z+ to see that the servo axis is rotating, and at the same time you can see that the large carriage is moving . Press Z+ again to see the axis stop. You can also monitor the status of the axis online in the Manager as shown in Figure 19 Online Monitoring.

Finally, use TCatScopeView for oscillography. First, establish four channel points, which are connected to the variables MAIN.AXIS1.NCTOPLC.ACTVELO and MAIN.AXIS1.NCTOPLC.ACTPOS, MAIN.AXIS2.NCTOPLC.ACTVELO and MAIN.AXIS2.NCTOPLC.ACTPOS. The variables are the actual speed and actual position of the two servo axes. Now test whether the edited program and the connected hardware device can execute.

The present invention will be further described below in conjunction with test experiments.

In the program, enter 2000 for the Z-axis Distance, 150 for the Velocity, 1500 for the X-axis, and 100 for the Velocity, and log into the program to start the test. Repeat the test 30 times to analyze the positioning accuracy of Z and X axes. One of the test results is shown in Figure 20 oscilloscope monitoring.

Figure 21 shows the positioning error of 30 tests, and its accuracy is 0.01mm. The data with the lowest Z and X axis errors are selected as the 23rd acquisition of the Z axis and the 4th acquisition of the X axis, respectively, and a linear analysis is made respectively. Tables 5 and 6 are the collected data. The results of the linear fitting are shown in Figures 22 and 23.

Table 5 Z-axis motion data

Table 6X-axis motion data

It can be seen from Figures 21, 22 and 23 that the linear fitting of the two servo axes is very high, and the r values are all in the interval of 0<r<1, which can predict the stability of the servo system in the entire stroke. , so the results of running the test meet the expected requirements. However, the control accuracy of the servo motor still needs to be improved. The reasons for the error include the low accuracy of the servo motor, the unreliable mechanical transmission, and the writing of the motion control program needs to be optimized.

Through the above test of the open-type electromechanical transmission control experimental platform, the results can meet the requirements of use, and the actual use process is also more convenient.

Other embodiments of the present disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or techniques in the technical field not disclosed by the present disclosure . The specification and examples are to be regarded as exemplary only, with the true scope and spirit of the disclosure being indicated by the appended claims.

It is to be understood that the present disclosure is not limited to the precise structures described above and illustrated in the accompanying drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure should be limited by the appended claims.

Claims (10)

1. An electromechanical transmission control method, characterized by comprising:

establishing an HMI (human machine interface) human-computer interaction interface, and setting motion parameters in motion control of an alternating current motor and motion control of a servo motor;

linking variables in motion control of the alternating current motor and motion control of the servo motor;

thirdly, the PLC control circuit receives the variable of the alternating current motor motion control, judges whether the alternating current motor reaches the expected rotating speed through the variable frequency speed regulating circuit, controls a proximity switch on a door of the variable frequency speed regulating circuit and regulates and controls the alternating current motor motion speed;

the PLC control circuit receives variables in the motion control of the servo motor, judges whether the servo motor moves according to set values through the servo control circuit, controls a proximity switch on a door of the servo control circuit and regulates and controls the motion speed and the position of the servo motor.

2. The electromechanical transmission control method according to claim 1, wherein after the third step, oscillography is performed by monitoring operation, state and operation data of the main circuit of the system, the servo control circuit, the variable frequency speed control circuit, the doubly fed controller circuit and the PLC control circuit through the touch screen.

3. The electromechanical transmission control method according to claim 1, wherein the alternating current motor motion control method includes:

step 1, setting motion parameters of motion control of an alternating current motor: setting the parameter of the frequency converter to be 1, and driving the frequency converter to operate by a terminal; setting the parameter of the frequency converter to be 3, changing the mode of receiving signals, and performing analog quantity access and voltage control;

step 2, linking variables for controlling the motion of the alternating current motor, wherein the variables comprise power supply frequency and induced electromotive force;

in step 3, the frequency conversion speed regulation circuit judges whether the alternating current motor reaches the expected rotating speed, and controls the amplitude and the frequency of the output voltage of the frequency converter through an acceleration and deceleration control mode, a V/f control mode and a pulse width modulation control mode so as to enable the frequency converter to output the voltage

E isThe induced electromotive force of the motor.

4. The electromechanical transmission control method according to claim 1, wherein the servo motor motion control method includes:

step 1), establishing an HMI (human machine interface), setting servo parameters, and inputting the current position of a Z axis: %. 2f,%. 2f represents the data type which is displayed as floating point number data type, and only the last two digits of decimal point are reserved;

step 2) setting the related variables and displaying the actual position of the X axis; selecting the IP of the servo driver, and displaying the current positions of the Z axis and the X axis on the HMI; and through a plurality of button controls, the servo motor shaft is enabled, jogged, relatively displaced and zeroed;

step 3) carrying out online monitoring on the servo motor shaft for enabling, rotating, moving the large carriage and stopping the shaft;

and step 4) performing oscillography, and respectively connecting variables MAIN.AXIS1.NCTOPLC.ACTVELO and MAIN.AXIS1.NCTOPLC.ACTPOS, and MAIN.AXIS2.NCTOPLC.ACTVELO and MAIN.AXIS2.NCTOPLC.ACTPOS to control the actual speed and the actual position of the servo axis.

5. An electro-mechanical transmission control system, comprising:

the system main circuit is used for connecting an external power supply with a main power supply breaker and then connecting the system power supply breaker, a servo power supply breaker and the main power supply breaker in parallel; a system power supply circuit breaker is formed to control the on-off of a low-voltage circuit, and a servo power supply circuit breaker is formed to control the on-off of a high-voltage circuit;

the servo control circuit controls the servo motor to move by adopting a servo driver so as to carry out controllable movement of the large carriage and the medium carriage;

the frequency conversion speed regulation circuit adopts a frequency converter to regulate the speed, and controls the rotating speed of the alternating current motor through an analog quantity output signal of the voltage doubling controller circuit;

the controller circuit controls the logic control of the servo driver and the frequency converter through digital signals and analog signals;

the PLC control circuit controls the proximity switches on the doors of the servo control circuit and the variable-frequency speed regulation circuit to carry out safety protection, and is connected with the lead of the system power supply circuit breaker, the servo control circuit and the variable-frequency speed regulation circuit to form a loop.

6. The electromechanical transmission control system of claim 5, wherein the system main circuit comprises: the main power circuit breaker is used for supplying power to the system;

the system power supply circuit breaker is used for controlling the PLC control circuit to be switched on and off;

the servo power supply circuit breaker is used for controlling the on-off of the frequency converter, the servo driver, the servo motor and the alternating current motor;

a fuse for protecting the circuit;

the switching power supply rectifies the alternating current 380V into the direct current 24V voltage.

7. The electro-mechanical transmission control system of claim 5, wherein the servo control circuit comprises:

the servo driver controls the servo motor to move; after the plurality of servo drivers lead out wiring from the servo power supply circuit breaker, the plurality of servo drivers are connected in parallel, and a network among the plurality of servers enables a network protocol to be communicated with the double-fortune controller circuit;

the encoder is used for encoding the network protocol and information for carrying out servo driver communication;

the proximity switch on the door is used for carrying out safety protection on the servo motor; the proximity switch on the door is controlled by a proximity sensor, and the servo motor stops working when the door is opened.

8. The electro-mechanical transmission control system of claim 5, wherein the variable frequency speed regulation circuit comprises:

the frequency converter is used for controlling the rotating speed of the alternating current motor; after a wiring is led out through a servo power supply circuit breaker, the two frequency converters are connected in parallel, and low-voltage control signals of the frequency converters are connected with a multiplying controller to control the running speed of the alternating current motor;

the blessing controller contact is used for outputting an analog quantity signal of the blessing controller;

the proximity switches on the two variable-frequency speed-regulating doors stop the alternating current motor when the door is opened;

the multiplying controller circuit comprises: the device comprises a coupler, an analog quantity output module, a communication module, a digital quantity input module and a digital quantity output module; the coupler is connected with a leading-out wiring of a system power supply circuit breaker; and data transmission and power supply are carried out among the analog quantity output module, the communication module, the digital quantity input module and the digital quantity output module through six contacts of the E-BUS.

9. The electro-mechanical transmission control system of claim 5, further comprising:

and the touch screen is used for monitoring the action, state and running data of the main circuit of the system, the servo control circuit, the variable frequency speed regulation circuit, the double-fortune controller circuit and the PLC control circuit and performing oscillography.

10. A computer device, characterized in that the computer device comprises a memory and a processor, the memory storing a computer program which, when executed by the processor, causes the processor to carry out the steps of:

establishing an HMI (human machine interface) human-computer interaction interface, and setting motion parameters in motion control of an alternating current motor and motion control of a servo motor;

linking variables in the motion control of the alternating current motor and the motion control of the servo motor;

the PLC control circuit receives the variable of the alternating current motor motion control, judges whether the alternating current motor reaches the expected rotating speed through the variable frequency speed regulating circuit, and controls a proximity switch on a door of the variable frequency speed regulating circuit to regulate and control the alternating current motor motion speed;

the PLC control circuit receives variables in the motion control of the servo motor, judges whether the servo motor moves according to set values through the servo control circuit, controls a proximity switch on a door of the servo control circuit and regulates and controls the motion speed and the position of the servo motor;

the oscillography is carried out through the action, the state and the operation data of the main circuit of the touch screen monitoring system, the servo control circuit, the frequency conversion and speed regulation circuit, the double-fortune controller circuit and the PLC control circuit.

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