Disclosure of Invention
The invention provides the distance measuring device with the temperature compensation function and the cutting system, solves the technical problem that distance measurement is influenced by temperature change, realizes the technical effects of keeping the cutting height stable and ensuring the cutting effect and the cutting quality.
The invention provides a distance measuring device with temperature compensation function, comprising: the circuit comprises a parasitic capacitor, a variable capacitance diode, a first resistor, a voltage source, an operational amplifier and a processor; the first end of the parasitic capacitor is connected with a distance measuring end, and the second end of the parasitic capacitor is connected with the signal input end of the operational amplifier; the variable capacitance diode is connected with the first resistor in parallel to form a parallel circuit; the parallel circuit is connected with the parasitic capacitor in parallel; the positive electrode of the variable capacitance diode is grounded, and the negative electrode of the variable capacitance diode is connected with the voltage source; and the signal output end of the operational amplifier is connected with the signal input end of the processor.
Further, still include: the driving circuit comprises a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor, a first driving voltage source and a second driving voltage source; the second end of the parasitic capacitor is connected with the input anode of the operational amplifier; a first end of the second resistor is connected with a negative electrode of the variable capacitance diode, and a second end of the second resistor is connected with the voltage source; the fifth resistor is connected with the first capacitor in series to form a series circuit; a first end of the series circuit is connected with a second end of the parasitic capacitor, and a second end of the series circuit is connected with a first end of the third resistor; the second end of the third resistor is connected with the input negative electrode of the operational amplifier, the second end of the third resistor is also connected with the first end of the fourth resistor, and the second end of the fourth resistor is grounded; the first end of the third resistor is also connected with the signal output end of the operational amplifier; one end of the first driving voltage source is grounded, and the other end of the first driving voltage source is connected with the operational amplifier; one end of the second driving voltage source is grounded, and the other end of the second driving voltage source is connected with the operational amplifier.
Further, the processor includes:
the frequency receiving module is used for receiving frequency data sent by the operational amplifier;
and the processing module is used for processing the frequency data to obtain distance data.
Further, the processing module is specifically configured to perform the following operations according to a formula
Calculating to obtain the distance data h; wherein, R is the equivalent resistance of the resonance circuit in the circuit, epsilon is the dielectric constant, s is the sectional area of the distance measuring end, k is the constant of the electrostatic force, and f is the received frequency data.
Further, the processor further includes:
and the data sending module is used for sending the distance data to a control end of the cutting mechanism.
Further, the operational amplifier is a UA741 operational amplifier.
The present invention also provides a cutting system comprising: the distance measuring device and the cutting mechanism are arranged; and the signal output end of the processor is in communication connection with the signal input end of the cutting mechanism.
Further, the cutting mechanism includes: a controller and a cutting actuator; the signal input end of the controller is in communication connection with the signal output end of the processor, and the signal output end of the controller is in communication connection with the signal input end of the cutting executing mechanism.
Further, the controller includes:
a data receiving module for receiving the distance data output by the processor;
and the instruction sending module is used for outputting an increase instruction to the cutting executing mechanism according to the distance data.
Further, the instruction sending module includes:
the database is used for storing the corresponding relation between different distances and the heightening instruction;
the query unit is used for querying the database according to the distance data to obtain a corresponding height-adjusting instruction;
and the instruction output unit is used for outputting the searched heightening instruction to the cutting executing mechanism.
One or more technical schemes provided by the invention at least have the following technical effects or advantages:
connecting a first end of the parasitic capacitor with a distance measuring end, and connecting a second end of the parasitic capacitor with a signal input end of the operational amplifier; the variable capacitance diode is connected with the first resistor in parallel to form a parallel circuit; the parallel circuit is connected with the parasitic capacitor in parallel; the positive electrode of the variable capacitance diode is grounded, and the negative electrode of the variable capacitance diode is connected with a voltage source; and the signal output end of the operational amplifier is connected with the signal input end of the processor. When the temperature changes, the change direction of the parasitic capacitance is opposite to that of the equivalent capacitance of the variable capacitance diode, and the parasitic capacitance and the equivalent capacitance of the variable capacitance diode are close in size, so that the influence of useless capacitance except capacitance between plates on the height measurement of the capacitance sensor due to temperature change can be compensated, the height measurement is more accurate, the stability of the cutting height is kept, and the cutting effect and the cutting quality are guaranteed.
Detailed Description
The embodiment of the invention provides the distance measuring device with the temperature compensation function and the cutting system, solves the technical problem that distance measurement is influenced by temperature change, realizes the technical effects of keeping the cutting height stable and ensuring the cutting effect and the cutting quality.
In order to solve the above problems, the technical solution in the embodiments of the present invention has the following general idea:
connecting a first end of the parasitic capacitor with a distance measuring end, and connecting a second end of the parasitic capacitor with a signal input end of the operational amplifier; the variable capacitance diode is connected with the first resistor in parallel to form a parallel circuit; the parallel circuit is connected with the parasitic capacitor in parallel; the positive electrode of the variable capacitance diode is grounded, and the negative electrode of the variable capacitance diode is connected with a voltage source; and the signal output end of the operational amplifier is connected with the signal input end of the processor. When the temperature changes, the change direction of the parasitic capacitance is opposite to that of the equivalent capacitance of the variable capacitance diode, and the parasitic capacitance and the equivalent capacitance of the variable capacitance diode are close in size, so that the influence of useless capacitance except capacitance between plates on the height measurement of the capacitance sensor due to temperature change can be compensated, the height measurement is more accurate, the stability of the cutting height is kept, and the cutting effect and the cutting quality are guaranteed.
For better understanding of the above technical solutions, the following detailed descriptions will be provided in conjunction with the drawings and the detailed description of the embodiments.
Referring to fig. 1, a distance measuring device with a temperature compensation function according to an embodiment of the present invention includes: parasitic capacitance C1Variable capacity, method of manufacturing the same, and electronic deviceThe circuit comprises a diode, a first resistor R1, a voltage source Vcc, an operational amplifier U1 and a processor; parasitic capacitance C1The first terminal of the first capacitor is connected with a distance measuring terminal and a parasitic capacitor C1The second end of the amplifier is connected with the signal input end of the operational amplifier U1; the variable capacitance diode is connected with the first resistor R1 in parallel to form a parallel circuit; parallel circuit and parasitic capacitance C1Parallel connection; the anode of the variable capacitance diode is grounded, and the cathode of the variable capacitance diode is connected with a voltage source Vcc; and the signal output end of the operational amplifier U1 is connected with the signal input end of the processor.
In the present embodiment, the parasitic capacitance C1A ceramic ring disposed over the nozzle is attached to the length of wire on the circuit board. And the signal output end of the operational amplifier U1 is connected with the signal input end of the processor through a radio frequency line.
The structure of the conversion circuit converting capacitance into frequency is further explained, referring to fig. 2, which further includes: a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first capacitor C3, a first driving voltage source VS1, and a second driving voltage source VS 2; parasitic capacitance C1The second end of the operational amplifier is connected with the input anode of the operational amplifier U1; a first end of the second resistor R2 is connected with the cathode of the variable capacitance diode, and a second end of the second resistor R2 is connected with a voltage source Vcc; the fifth resistor R5 is connected with the first capacitor C3 in series to form a series circuit; first end of series circuit and parasitic capacitance C1A second end of the series circuit is connected to a first end of a third resistor R3; the second end of the third resistor R3 is connected with the input negative electrode of the operational amplifier U1, the second end of the third resistor R3 is also connected with the first end of the fourth resistor R4, and the second end of the fourth resistor R4 is grounded; the first end of the third resistor R3 is also connected with the signal output end of the operational amplifier U1; one end of a first driving voltage source VS1 is grounded, and the other end of the first driving voltage source VS1 is connected with an operational amplifier U1; one end of the second driving voltage source VS2 is grounded, and the other end of the second driving voltage source VS2 is connected to the operational amplifier U1.
To further explain the structure of the conversion circuit converting capacitance into frequency, the sixth resistor R7 and the parasitic capacitor C1And (4) connecting in parallel.
To explain in detail the process of obtaining distance data from frequency data, the processor comprises:
the frequency receiving module is used for receiving frequency data sent by the operational amplifier U1;
and the processing module is used for processing the frequency data to obtain distance data.
Further illustrating the process of obtaining distance data from frequency data, the processing module is specifically configured to obtain distance data according to a formula
Calculating to obtain distance data h; wherein, R is the equivalent resistance of the resonance circuit in the circuit, epsilon is the dielectric constant, s is the sectional area of the distance measuring end, k is the constant of the electrostatic force, and f is the received frequency data.
In order to send the obtained distance data to the control end of the cutting mechanism, thereby realizing the self-adaptive adjustment of the distance between the nozzle and the processed workpiece, the processor further comprises:
and the data sending module is used for sending the distance data to the control end of the cutting mechanism.
In this embodiment, the op-amp U1 is a UA741 op-amp. The type of the varactor, the magnitude of the voltage source Vcc, and the resistances and types of the first resistor R1 and the second resistor R2 are determined according to actual conditions after specific analysis.
An embodiment of the present invention further provides a cutting system, including: the distance measuring device and the cutting mechanism are arranged; and the signal output end of the processor is in communication connection with the signal input end of the cutting mechanism.
Specifically explaining the structure of the cutting mechanism, the cutting mechanism includes: a controller and a cutting actuator; the signal input end of the controller is in communication connection with the signal output end of the processor, and the signal output end of the controller is in communication connection with the signal input end of the cutting executing mechanism.
In this embodiment, the signal output terminal of the processor is communicatively connected to the signal input terminal of the controller via an EtherCAT bus.
Specifically explaining the structure of the controller, the controller includes:
a data receiving module for receiving the distance data output by the processor;
and the instruction sending module is used for outputting an increase instruction to the cutting executing mechanism according to the distance data.
The output process of the heightening instruction is specifically explained, and the instruction sending module comprises:
the database is used for storing the corresponding relation between different distances and the heightening instruction;
the query unit is used for querying the database according to the distance data to obtain a corresponding height-adjusting instruction;
and the instruction output unit is used for outputting the searched heightening instruction to the cutting executing mechanism.
In this embodiment, the controller is a control center of the laser cutting machine, and can control the movement of each directional axis. When the height value between the nozzle and the workpiece in the vertical direction is known, the difference between the current height and the target height can be judged, so that the Z axis is adjusted to move to the target height, for example, the target height is 5mm, the current height is 1mm, the Z axis is controlled to move upwards by 4mm, and the height adjusting function is achieved.
The temperature compensation principle of the distance measuring device with the temperature compensation function provided by the embodiment of the invention is explained as follows:
referring to fig. 3, the varactor disposed at the input port of the capacitor is equivalent to an equivalent capacitor C2. When a reverse bias is applied across the varactor, a capacitive effect is created, and generally the capacitance of the varactor decreases as the reverse bias increases. The first resistor R1 is a resistor with small temperature coefficient and basically unchanged resistance value when the temperature changes, the second resistor R2 is a temperature-sensitive resistor with negative temperature coefficient, the resistance value of the resistor decreases along with the increase of the temperature, the voltage source Vcc is a direct current voltage source, and the capacitance value C of the varactor diode2Mainly affected by the voltage across the first resistor R1.
The distance to be measured is h + Δ h1+ Δ h2, where h is the interplate capacitance C between the nozzle 2 and the workpiece 30The actual height value of interest, Δ h1, is the parasitic capacitance C on the cable from the ceramic ring 1 above the nozzle 2 to the circuit board1Height due to temperature changeError, Δ h2, is the equivalent capacitance C with the varactor2The associated altitude compensation is used to compensate for the error ah 1. In practical use, assuming that the height h is unchanged, the capacitance C between the plates increases as the temperature increases0Since it is mainly height dependent, there is essentially no change. Parasitic capacitance C1Since the deformation of the ceramic ring 1 generally increases with the temperature, the second resistor R2 decreases with the temperature, and the first resistor R1 remains unchanged, the voltage across the first resistor R1 increases, resulting in the equivalent capacitance C2And decreases. When the parasitic capacitance C1Increased capacitance and equivalent capacitance C2When the reduced capacitance is very close, a capacitance compensation effect can be achieved, and the finally obtained height value is close to the actual height value. The same principle is used when the temperature is reduced, and the effect of capacitance compensation can be achieved. The core of the embodiment of the invention is that the parasitic capacitance C changes along with the temperature1Is varied by the equivalent capacitance C2The change directions are opposite, and the sizes are similar, so that the influence of useless capacitance except the capacitance between the plates on the measurement height of the capacitance sensor due to temperature change can be compensated, the height measurement is more accurate, the stability of the cutting height is kept, and the cutting effect and the cutting quality are ensured.
[ technical effects ] of
A parasitic capacitance C1The first terminal of the first capacitor is connected with a distance measuring terminal and a parasitic capacitor C1The second end of the amplifier is connected with the signal input end of the operational amplifier U1; the variable capacitance diode is connected with the first resistor R1 in parallel to form a parallel circuit; parallel circuit and parasitic capacitance C1Parallel connection; the anode of the variable capacitance diode is grounded, and the cathode of the variable capacitance diode is connected with a voltage source Vcc; and the signal output end of the operational amplifier U1 is connected with the signal input end of the processor. When the temperature changes, the parasitic capacitance C1The change of the capacitance sensor is opposite to the change direction of the equivalent capacitance of the variable capacitance diode, and the size of the capacitance sensor is close to the change direction of the equivalent capacitance of the variable capacitance diode, so that the influence of useless capacitance except the capacitance between plates on the measurement height of the capacitance sensor due to temperature change can be compensated, the height measurement is more accurate, the cutting height is kept stable, and the cutting effect and the cutting quality are guaranteed.
As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.