CN1283490C - Composite automobile instrument and vehicle multifunction information platform based on virtual and digital technology - Google Patents

Abstract

The invention relates to a car instrument based on virtual and digital technology. The combination car instrument and vehicle multi-function information platform based on virtual and digital technology is characterized in that: the liquid crystal display is connected with the vehicle computer through the AGP slot by the graphics card; the touch screen is connected with the vehicle computer through the serial port; the indicator light switch is connected with the digital I through the signal line The /O data acquisition card is connected, and the digital I/O data acquisition card is connected with the on-board computer through the PCI slot; the wheel speed sensor is connected with the on-board computer through the serial port; the battery monitoring system is connected with the on-board computer through the serial port; Input the TV card, the TV card is connected with the vehicle computer through the PCI slot; the GPS receiver is connected with the vehicle computer through the USB interface; the wireless network card is connected with the vehicle computer through the USB interface. The invention integrates the automobile instrument and various information functions into one.

Description

Combined car instrument and vehicle multifunctional information platform based on virtual and digital technology

technical field

The invention is a multifunctional instrument for automobiles based on virtual technology and digital technology, and belongs to the category of multifunctional combined instruments for automobiles.

Background technique

The car instrument is the window for the driver to communicate with the car. The development of the car instrument has gone through four stages: the working principle of the first generation of car instrument is based on the mechanical principle, which is a mechanical instrument; the second generation of car instrument is based on the principle of electrical measurement. That is, through various sensors, the non-electrical physical quantity to be measured is converted into an electrical signal for measurement. It is an electrical instrument; the third generation is an analog circuit electronic instrument; the fourth generation is a stepping motor type full digital automotive instrument. Existing stepping motor-type full-digital automotive instruments often use mechanical or electronic physical instruments, indicators and signaling devices, and mechanical or electrical failures will still occur, which will affect the accuracy and reliability of their measurement indications. Therefore, the performance It needs to be further improved.

In order to improve the function of the instrument, there should be an alarm system, to judge the cause of the accident, there should be a driving record, to improve the driving conditions, there should be an electronic rear view device, and for the convenience of travel, an on-board office system (wireless Internet access) and so on should be required. Some of these single in-vehicle systems have been applied in automobiles, but there is still no car instrumentation and information comprehensive platform based on virtual and digital technology that integrates car instrumentation and various information functions.

Contents of the invention

The object of the present invention is to provide a combined vehicle instrument and vehicle multifunctional information platform based on virtual and digital technology, which integrates the vehicle instrument and various information functions.

In order to achieve the above object, the technical solution of the present invention is: a combined vehicle instrument and a vehicle-mounted multifunctional information platform based on virtual and digital technology, characterized in that: the liquid crystal display is connected with the vehicle-mounted computer by the graphics card through the AGP slot, and the liquid crystal display shows that the vehicle is running The status monitoring interface and man-machine operation interface; the touch screen is connected to the on-board computer through the serial port; the indicator switch is connected to the digital I/O data acquisition card through the signal line, and the digital I/O data acquisition The I/O data acquisition card provides digital I/O functions, which collect: various lighting and signal indicator switches (left turn signal, right turn signal, high beam, low beam, side lights, front fog lights, parking lights , reversing light, windshield wiper indicator light), each alarm signal indicator switch (brake system failure light, door ajar indicator light, seat belt not fastened indicator light, hazard warning light), motor failure and the gear signal of the motor; the wheel speed sensor adopts a magnetoelectric speed sensor, which is installed on the half shaft and connected with the on-board computer through the serial port to measure the rotational angular velocity of the wheel; the battery monitoring system is connected with the on-board computer through the serial port, which is used for Monitor the SOC (State Of Charge), temperature, voltage and current of the battery; the camera inputs electrical signals into the TV card through the AV terminal, and the TV card is connected to the on-board computer through the PCI slot, and the camera acts as a rearview mirror; GPS receiver The device is connected to the on-board computer through the USB interface, and the GPS receiver receives the vehicle positioning signal sent by the Global Positioning System (GPS), and then draws the vehicle positioning point on the electronic map through map matching technology; the wireless network card communicates with the vehicle through the USB interface. The on-board computer is connected, and the wireless network card (CDMA Modem) enables the on-board computer to be connected to the Internet through the CDMA 1X network.

There are 1-7 liquid crystal displays.

When there is one liquid crystal display, the screen is divided into an electronic rearview mirror area, a positioning navigation (electronic map) area, a speedometer area, a battery working state monitoring area, a lighting and signal indicator area, and an alarm signal indicator area. Area, program control area, the touch screen is fixed on the LCD screen; the electronic rearview mirror area displays the rear image of the car captured by the camera, so that the driver can observe the traffic conditions behind the car; the positioning navigation area displays an electronic map, which uses a GPS receiver to receive The car positioning information depicts the car running track on the electronic map; the speedometer area displays the speedometer, overspeed warning light, single-trip odometer and cumulative odometer with reset button; the battery working status monitoring area displays the battery state of charge SOC (State Of Charge) and battery temperature; the lighting and signal indicator area displays the status of the following indicators: left turn signal, right turn signal, high beam, low beam, side lights, front fog lights, parking lights, reverse lights , gear position indicator light and windshield wiper indicator light; the warning signal indicator area displays the status of the following indicators: brake system fault indicator light, door ajar indicator light, seat belt not fastened indicator light, hazard warning light and motor failure light; the program control area displays the operation buttons of the following programs: electronic rearview mirror, vehicle positioning navigation, vehicle operation record (black box), Internet browser, MP3 player, wireless TV and FM radio.

The vehicle-mounted computer is a small desktop computer or an embedded computer.

The invention is a virtual instrument, which realizes the collection, analysis, processing and display of vehicle operation information in a digital way, and has the characteristics of simple structure and stable operation. Rearview mirror, on-board positioning and navigation, fault monitoring, wireless Internet access, audio-visual entertainment, operating records and other systems are integrated, and a vehicle-mounted computer is shared to form a combined vehicle instrument and vehicle-mounted multi-functional information platform based on virtual and digital technology. The instrument and various information functions are integrated, which can achieve the purpose of simplifying the structure, reducing the cost, improving the reliability and realizing the multi-function.

Description of drawings

Figure 1 is a block diagram of the human-machine interface of the system taking pure electric vehicles as an example

Figure 2 is a block diagram of the hardware system

Figure 3 is a block diagram of the software system

Figure 4 is a block diagram of the application software

Detailed ways

As shown in Figure 2, based on the combination of virtual and digital technology, the car instrument and the car multi-function information platform, the liquid crystal display is connected with the car computer through the AGP slot by the graphics card, and the liquid crystal display shows the car running status monitoring interface and the man-machine operation interface; the touch screen It is connected with the on-board computer through the serial port; the indicator light switch is connected with the digital I/O data acquisition card through the signal line, and the digital I/O data acquisition card is connected with the on-board computer through the PCI slot, and the digital I/O data acquisition card provides digital I/O O function, it collects: various lighting and signal indicator switches (left turn signal, right turn signal, high beam, low beam, side lights, front fog lights, parking lights, reversing lights, windshield wiper indicator light), each alarm signal light switch (brake system failure light, door not closed light, seat belt not fastened light, hazard warning light), motor fault and motor gear signal; the wheel speed sensor adopts The magnetoelectric speed sensor is installed on the half shaft and connected to the on-board computer through the serial port to measure the rotational angular velocity of the wheel; the battery monitoring system is connected to the on-board computer through the serial port, which is used to monitor the SOC (State Of Charge) of the battery Charge), temperature, voltage and current; the camera inputs electrical signals into the TV card through the AV terminal, and the TV card is connected to the on-board computer through the PCI slot, and the camera acts as a rearview mirror; the GPS receiver is connected to the on-board computer through the USB interface. The GPS receiver receives the car positioning signal sent by GPS (Global Position System), and then draws the car positioning point on the electronic map through map matching technology; the wireless network card is connected to the vehicle-mounted computer through the USB interface, and the wireless network card (CDMA Modem ) to connect the vehicle-mounted computer to the Internet through the CDMA 1X network.

As shown in Figure 1, there is one LCD display, which is divided into electronic rearview mirror area, positioning navigation (electronic map) area, speedometer area, battery working status monitoring area, lighting and signal indicator area, and alarm signal indicator Area, program control area, the touch screen is fixed on the LCD screen; the electronic rearview mirror area displays the rear image of the car captured by the camera, so that the driver can observe the traffic conditions behind the car; the positioning navigation area displays an electronic map, which uses a GPS receiver to receive The car positioning information depicts the car running track on the electronic map; the speedometer area displays the speedometer, overspeed warning light, single-trip odometer and cumulative odometer with reset button; the battery working state monitoring area displays the battery state of charge SOC (StateOf Charge) and battery temperature; the lighting and signal indicator area displays the status of the following indicators: left turn signal, right turn signal, high beam, low beam, side lights, front fog lights, parking lights, reverse lights, Gear position indicator light and windshield wiper indicator light; the warning signal indicator area displays the status of the following indicator lights: brake system fault light, door ajar light, seat belt not fastened light, hazard warning light and Motor failure light; the program control area displays the operation buttons of the following programs: electronic rearview mirror, vehicle positioning navigation, vehicle operation record (black box), Internet browser, MP3 player, wireless TV and FM radio.

The vehicle-mounted computer adopts a small desktop computer (such as adopting embedded technology, which can further reduce volume and cost). Various indicator light switch signals are transmitted to the computer through the digital I/O data acquisition card, and various analog signals (such as wheel speed, battery voltage, current and temperature, etc.) are transmitted to the computer through corresponding sensors. Data and signals are displayed on the man-machine interface (liquid crystal display) after being processed by computer software and hardware. In this example, the human-machine interface is a single screen, and multiple screens can also be used. In this example, the man-machine interface is divided into 7 areas, which display different information and vehicle operation data respectively. The start button of each function is located on the touch screen, and the driver can easily start the corresponding program through the touch screen to obtain the required dynamic information. The car instruments are all virtual and can be displayed on the man-machine interface (liquid crystal display).

The invention integrates the virtual digital vehicle instrument with additional information systems such as electronic rearview mirror, vehicle positioning and navigation, fault monitoring, wireless Internet access, audio-visual entertainment, and running records, so that they can share the vehicle computer resources in primary and secondary, divided into regions and Time-sharing vehicle LCD display. In the system integration, the virtual digital car instrument, electronic rearview mirror, vehicle positioning navigation and fault monitoring system closely related to the driver's driving safety should be the main ones, supplemented by wireless Internet access and audio-visual entertainment systems.

Through reasonable system integration and selection of components suitable for vehicle use and cost-effective, the overall performance of the system can be improved and the overall cost of the system can be reduced.

The monitoring unit of each signal and each sub-functional unit of the system are regarded as mutually independent sub-modules, and each sub-module can work independently, and can also be combined into a system according to a certain connection. Modularization is manifested in the modular integration of each board in terms of hardware structure, and in the form of virtual instrument structure in terms of system software integration. This modular design improves system reliability, maintainability, and testability.

On the one hand, due to the continuous enrichment of automotive instrument functions, it is necessary to consider the scalability of the system in the design, and improve the upgrade performance and cost performance of the system. On the other hand, in order to obtain an economical and practical small system, it is necessary to consider the simplification of the system in the design, and reduce the cost and price on the premise of ensuring the basic functions of the system. The scalability and simplification of the system are reflected in the compatibility between system software and hardware, as well as the flexible connection between software and hardware.

The virtual digital car meter should be a kind of general-purpose car meter that can basically meet various car models. As long as the relevant parameters are appropriately modified in the software for different car models, the main structure of the software and hardware does not need to be changed, and the general-purpose car meter can be used. Matches and satisfies the car model. In this way, complex processes such as redesigning, debugging and reliability testing of automotive instrumentation for different models can be omitted, and the time and cost of product development can be shortened to the greatest extent, while possible technical risks can be avoided.

The system should be able to meet the requirements of the automobile instrument durability test in the national and automobile industry standards, and can run continuously and reliably for 24 hours. By taking good shielding and protection measures for the system hardware, it has reliable anti-interference ability. By backing up the system software, it has self-recovery capability.

The system should be able to withstand the fixed frequency vibration test in the three directions of up and down, left and right, and front and back, and the sweep frequency vibration test in the up and down direction. After the vibration test, the hardware must not be loose or damaged, and the working performance of the system should comply with the relevant national and automotive industry standards.

The system should be able to work normally at an ambient temperature of -20°C to 55°C, and its working performance should meet the requirements of the relevant national and automotive industry standards.

The system should have strong compatibility, and can be used in conjunction with hardware and software that may be added in the future under the Windows operating system to expand system functions.

The present invention collects the non-electric quantity physical quantity to be measured through the sensor, realizes the transmission, analysis, processing and display of the vehicle operation information in a digital way, and combines the virtual instrument VI (Virtual Instrument) technology, replaces the corresponding physical objects with virtual indicators and signal devices, and constructs a virtual digital instrumentation. Simultaneously, the present invention expands the function on the basis of the automobile instrument, combines the electronic rearview mirror, vehicle positioning and navigation, fault monitoring and diagnosis, driving records, wireless Internet access (vehicle office system), and audio-visual entertainment system together, and is controlled by the vehicle computer Unified control. In this way, it is combined into a virtual and digital technology-based combined car instrument and vehicle multi-function information platform with 7 functions (functions can be increased or decreased).

1. The human-machine interface and functions of the system

The human-machine interface of the system is a bridge for information exchange between the driver and the system. The real object developed by the present invention adopts a single large-screen display screen, and may also adopt the form of multiple screens. The man-machine interface of the system is divided into 7 zones according to the functions. The driver’s requirements (safe driving and convenient operation) are fully considered in the interface design and partitioning to ensure that the output information display is intuitive and eye-catching and the driver’s operation is accurate.

Figure 1 is a block diagram of the human-machine interface of the system taking pure electric vehicles as an example (traditional vehicles only need to change the information display of battery SOC and battery temperature gauge to parameters such as fuel tank oil volume and engine coolant temperature).

The HMI is divided into 7 areas:

1. Electronic rearview mirror area

The electronic rearview mirror area displays the rear image of the car captured by the camera, so that the driver can observe the traffic conditions behind the car. When the driver engages the reverse gear, the electronic rearview mirror area will automatically display in full screen, which is convenient for the driver to reverse the car.

2. Positioning and navigation (electronic map) area

The positioning navigation area displays an electronic map, which uses the vehicle positioning information received by the GPS receiver to describe the vehicle's running track on the electronic map. The positioning navigation program can provide a static navigation function, which can automatically determine the shortest driving route according to the starting point and ending point names provided by the driver.

3. Speedometer area

The speedometer area displays the speedometer, overspeed warning light, one-way odometer with reset button and cumulative odometer.

The speedometer calculated with the theoretical formula should be corrected through the real vehicle test. When the vehicle speed is an integer multiple of 10km/h, there will be a voice prompt "xxkm/h" to inform the driver. When the vehicle speed exceeds a certain limited high speed, the overspeed warning light will light up, and an overspeed alarm voice prompt "Please note that the vehicle speed exceeds xxkm/h" will be issued.

The one-way odometer displays the mileage of a single trip, and the one-way odometer can be reset to zero by pressing the reset button.

The cumulative odometer displays the cumulative total mileage of the car.

4. Battery working status monitoring area

The battery working status monitoring area displays the battery state of charge SOC (State Of Charge) and battery temperature. When the battery SOC is lower than the SOC lower limit (such as 40%), the battery power is insufficient, the battery SOC meter is displayed in red, and there will be a voice prompt "Please note that the battery is insufficient" to remind the driver to pay attention. When the battery SOC is higher than the SOC upper limit (such as 80%), the battery power is sufficient, and the battery SOC meter is displayed in green. When the battery SOC is between the SOC upper and lower limits (such as 40% to 80%), the battery power is normal, and the battery SOC meter is displayed in blue. When the battery temperature is higher than a certain upper limit, the battery is overheated, the battery temperature gauge will display in red, and there will be a voice prompt "Please note that the battery is overheated". When the battery temperature is lower than the temperature upper limit, the battery temperature is normal, and the battery temperature gauge is displayed in green.

5. Lighting and signal indicator area

The lighting and signal indicator area shows the status of the following indicators: left turn signal, right turn signal, high beam, low beam, side lights, front fog lights, parking lights, reverse lights, gear indicator and windshield Glass wiper indicator light. Their signs (shape and color) should comply with GB4094-1999 "Signs of Automobile Controls, Indicators and Signaling Devices". When the switch of a certain light is closed and the light can work normally, there will be a voice prompt "xx light is on".

6. Alarm signal indicator area

The warning signal indicator area displays the status of the following indicators: Brake system failure indicator, door ajar indicator, seat belt not fastened indicator, hazard warning indicator and motor failure indicator. Their signs (shape and color) should comply with GB4094-1999 "Signs of Automobile Controls, Indicators and Signaling Devices". When a component is faulty, there will be a voice prompt "Please note that xx is faulty".

7. Program control area

The program control area displays the operation buttons of the following programs: electronic rearview mirror, vehicle positioning navigation, vehicle operation record (black box), Internet browser, MP3 player, wireless TV and FM radio. Pressing a button starts the corresponding program. The stop button in this area is used to stop the virtual digital car instrument software from running.

In order to ensure driving safety, the Internet browser and the wireless TV program cannot be operated during driving, so as to prevent the windows of the two from occupying the screen and interfering with the driver's line of sight.

The car running recorder can indicate and record the driving speed, distance and corresponding time of the car, and it can be used as a black box to analyze car traffic accidents.

2. Hardware system

The selection and combination principles of the system hardware are: fully consider the compatibility and cost performance of each hardware; fully consider the electromagnetic compatibility of the system to ensure that the system can work normally in a relatively harsh electromagnetic environment; meet the seven basic functional requirements of the system, and Fully consider the scalability and simplification of the system, and reserve several scalable interfaces. Figure 2 is a structural block diagram of the hardware system, which includes the following main components.

1. On-board computer

The on-board computer adopts a small desktop computer, its CPU is AMD Athlon 2000+XP, the main frequency is 2.0GHz; the memory capacity is 512M; the motherboard is KM400A-8235, integrated graphics card, sound card and network card, providing 3 PCI slots and 1 AGP slot, several serial and USB ports. Embedded technology can also be applied. If the embedded operating system and corresponding microprocessor and other software and hardware are used, the system cost and volume can be reduced, which is conducive to its application in automobiles.

2. LCD display

The liquid crystal monitor displays the vehicle running status monitoring and the man-machine operation interface, and it and the graphics card are connected with the vehicle-mounted computer through the AGP slot.

3. Touch screen

The touch screen acts as a mouse, and it determines the position of the cursor on the LCD screen by measuring the position of the touch point on the touch screen. The driver can conveniently operate the on-board computer by clicking on the touch screen. The touch screen is fixed on the liquid crystal display screen, and is connected with the on-board computer through the serial port.

4. Digital I/O data acquisition card

Digital I/O data acquisition cards provide digital I/O functionality. It is connected to the on-board computer through a PCI slot. The pure electric vehicle signals it collects include: various lighting and signal indicator switches (left turn signal, right turn signal, high beam, low beam, side lights, front fog lights, parking lights, reversing lights, windshield Glass wiper indicator light), each alarm signal indicator switch (brake system fault light, door ajar indicator light, seat belt not fastened indicator light, hazard warning light), motor fault and motor gear signal.

5. Wheel speed sensor

The wheel speed sensor adopts a magnetoelectric speed sensor to measure the rotational angular velocity of the wheel. It is mounted on the half shaft and connected to the on-board computer through a serial port.

6. Battery monitoring system

The battery monitoring system matched with the on-board battery (such as Ni-MH battery) is used to monitor the state of charge SOC (State Of Charge), temperature, voltage and current of the battery. It is connected with the on-board computer through the serial port.

7. Camera

The camera acts as a rearview mirror. It uses a charge-coupled device (CCD) image sensor to convert light signals into electrical signals, and then inputs the electrical signals into the TV card through the AV terminal. The captured images are reproduced on the LCD screen in real time.

8. TV card

The TV card can receive wireless TV signals, AV terminal signals, S terminal signals and FM broadcast signals, and it can play wireless TV, images captured by cameras and FM broadcasts through corresponding video and audio software. It is connected to the on-board computer through a PCI slot.

9. GPS receiver

The GPS receiver receives the car positioning signal sent by GPS (Global Position System), and then draws the car positioning point on the electronic map through map matching technology. It is connected to the on-board computer via a USB interface.

10. Wireless network card

The wireless network card (CDMA Modem) connects the on-board computer to the Internet through the CDMA 1X network. It is connected to the on-board computer via a USB interface.

3. Software system

1. The composition of the software system

As shown in Figure 3, the software system is mainly composed of three parts: operating system, hardware driver and application software. The operating system adopts Windows2000, which is a multi-tasking operating system and supports a variety of hardware devices. Hardware drivers are provided by hardware manufacturers. Application software includes virtual digital vehicle instrumentation and vehicle multifunctional information platform application software, vehicle positioning and navigation software, Internet browser, video and audio playback software.

2. Virtual digital combined vehicle instrument and vehicle multifunctional information platform software

The development tool of the virtual digital combined vehicle instrument and the vehicle multifunctional information platform software adopts LabVIEW of NI (National Instrument), which provides a graphical software development environment for virtual instruments. The software is designed according to the programming principles of structured, modularized and generalized programming, from top to bottom, step by step refinement, until coding. Through programming, the software can call other application software.

As shown in Figure 4, the structure of the virtual digital vehicle instrument and the application software of the vehicle multifunctional information platform can be divided into a main control module, an event capture module, an event processing module and a data storage module.

The main control module mainly controls and coordinates the operation of other modules in the program.

The event capture module mainly monitors, identifies and reports the occurrence of external or internal events, and then notifies the main control module, and the main control module then activates the corresponding thread in the event processing module to respond to external or internal events.

The event processing module is the main body of the application software function realization, and it is composed of several function sub-modules loosely coupled together, and the function sub-modules include calls to other application programs. It executes specific sub-modules to achieve certain functions under the trigger of external or internal events.

The data storage module is mainly used to store some important operating data (such as vehicle speed, mileage, driving track, etc.) and fault alarm records, so as to facilitate post-event statistical analysis, fault analysis and diagnosis.

Real-time multitasking systems provide application software with a mechanism for controlling and responding to multiple, discrete events in the real world. Each task has an independent thread, and the tasks run independently and coordinate with each other. During the design process of application software, problems such as low system efficiency, sharing conflicts, task termination or system crash due to inappropriate use of system resources or unreasonable program structure design should be avoided to ensure that the system works in real time, efficiently and reliably.

The vehicle speed odometer in the event processing module, the battery monitoring system and the indicator light status display module and the operation record data storage module in the data storage module are described in detail as follows.

(1) Speedometer

The speedometer uses a magnetoelectric speed sensor to measure the rotational angular velocity (r/min) of the wheel. The speed sensor is installed on the half shaft, and every time the half shaft rotates one circle, the speed sensor sends a pulse to the lower computer (single chip microcomputer) connected to it. The lower computer of the speedometer measures the multiple n of the timing base 0.05s contained in the time interval between the rising edges of each pulse, then the pulse period (s) T=0.05n. Correspondingly, wheel speed (r/min) $\mathrm{\ω}=\frac{1}{0.05\mathrm{no}}\×60=\frac{1200}{\mathrm{no}},$

Vehicle speed(km/h)

${\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0.377</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; r</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; \&omega;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0.377</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; r</span>}<span\; class="notranslate">\; \&times;</span>\frac{\mathrm{<span\; class="notranslate">\; 1200</span>}}{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

Among them: r is the wheel radius (m).

At the same time, the lower computer also counts the number of pulses sent by the speed sensor to obtain the total number of turns m of the wheel, then the mileage (km)

S = 2π×r×m/1000 (2)

The lower computer is connected to the serial interface RS-232 of the upper computer through the RS485-RS232 adapter, and the upper computer (vehicle computer) reads the n and m values measured by the lower computer of the speedometer through the serial interface RS-232, and then press Formulas (1), (2) calculate vehicle speed and mileage, and display their values on the virtual instrument interface.

The following serial port communication protocol is followed between the upper computer and the lower computer:

d. Serial port settings

The baud rate is 9600bps, the data bit is 8 bits, the stop bit is 1, and there is no flow control.

e. The upper computer sends instructions to the lower computer

The upper computer sends the following 3 bytes to the lower computer in turn, and the delay is 10ms after each byte is sent.

The first byte is 32 (hexadecimal number), which is the address number of the lower computer of the speedometer. The serial port parity bit is set to Mark.

The second byte is C5 (hexadecimal number), which is a command that requires the lower computer to send data. The serial parity bit is set to Space.

The third byte is F7 (hexadecimal number), which is the check code formed by the XOR of the first byte (address number) and the second byte (command), that is, 32 XOR C5=F7 . The serial parity bit is set to Space.

f. The lower computer sends data to the upper computer

After the lower computer receives the above 3 bytes sent by the upper computer, it sends data n and m to the upper computer. The data sent by the lower computer to the upper computer follows the following format: n_L-n_H-m_LL-m_LH-m_HL-m_HH-check, where: n_L and n_H are the 2nd and 1st of the hexadecimal numbers corresponding to n in formula (1). bytes; m_LL, m_LH, m_HL, m_HH are the 4th, 3rd, 2nd, 1st bytes of the hexadecimal number corresponding to m in formula (2); the check code check is n_L, n_H, m_LL, Exclusive OR of m_LH, m_HL, m_HH.

(2) Battery monitoring system

The lower computer (single chip microcomputer) of the battery monitoring system uses voltage sensors, current sensors and temperature sensors to measure the working voltage, current and temperature of the battery respectively, and its upper computer calculates the SOC of the battery according to the above parameters. An example is now used to illustrate the working principle of the battery monitoring system. Divide the 280-cell Ni-MH batteries on the vehicle into 40 groups (7 cells in each group), and install a lower computer for measuring voltage and temperature on each group of batteries. The lower computer can measure the voltage of each battery in the battery group and the The temperature of the battery pack. A lower computer for measuring the current of the battery stack is installed on the entire battery stack.

The 41 lower computers of the battery monitoring system are all connected to a network cable, which is connected to the serial port of the upper computer through the RS485-RS232 adapter, and the upper computer and the lower computer form a bus network in this way. The upper computer sends commands to the lower computer through "roll call", and the corresponding lower computer sends the data required by the upper computer to the upper computer after receiving the command from the upper computer.

The upper computer (vehicle computer) reads the voltage, current and temperature values measured by the lower computer of the battery monitoring system through the serial interface RS-232 according to the following serial port communication protocol.

c. Serial port settings

The baud rate is 9600bps, the data bit is 8 bits, the stop bit is 1, and there is no flow control.

d. The upper computer sends instructions to the lower computer

When measuring voltage and temperature, the upper computer sends the following 3 bytes to the lower computer in sequence, and delays 10ms after each byte is sent.

The first byte is the address number, that is, the address number of the battery pack is 01~28 (hexadecimal number). The serial port parity bit is set to Mark.

The second byte is the command C3 (hexadecimal number), indicating that the lower computer is required to send voltage and temperature data. The serial parity bit is set to Space.

The third byte is the check code (hexadecimal number), which is the XOR of the first byte (address number) and the second byte (command). The serial parity bit is set to Space.

When measuring the current, the upper computer sends the following 3 bytes to the lower computer in turn, with a delay of 10ms after each byte is sent.

The first byte is the address number 29 (hexadecimal number) of the lower computer for current measurement. The serial port parity bit is set to Mark.

The second byte is the command C4 (hexadecimal number), indicating that the lower computer is required to send current data. The serial parity bit is set to Space.

The third byte is the check code ED (hexadecimal number), which is the XOR of the first byte (address number) and the second byte (command), that is, 29 XOR C4=ED. The serial parity bit is set to Space.

e. The lower computer sends data to the upper computer

The A/D conversion of the lower computer is 10 bits, and the reference voltage is 3.3V.

After the lower computer receives the above-mentioned 3 bytes sent by the upper computer, it sends the data required by the upper computer to the upper computer.

The data (16 bytes) sent by the lower computer for measuring voltage and temperature to the upper computer follows the following format: the voltage high (2bit) and low (8bit) of the voltage of the first battery in the group, ..., the seventh battery in the group The high bit (2bit) and low bit (8bit) of the voltage, the high bit (2bit) and low bit (8bit) of the temperature of the battery.

The data (2 bytes) sent by the lower computer for current measurement to the upper computer follows the following format: the current high bit (2bit) and low bit (8bit) of the battery.

After the upper computer receives the data sent by the lower computer, it calculates the voltage, current, temperature and SOC according to the following formulas:

Single battery voltage (V) $V=\frac{V_{\mathrm{HEX}}}{1024}\&times;3.3\&times;0.5---\left(3\right)$

Battery current (A) $I=\frac{I_{\mathrm{HEX}}}{1024}\&times;200---\left(4\right)$

Battery temperature (℃) $T=\frac{T_{\mathrm{HEX}}}{1024}\&times;3.3\&times;100---\left(5\right)$

In the formula: V _HEX , I _HEX , _THEX are the hexadecimal numbers of the voltage, current and temperature data received by the upper computer and sent by the lower computer, respectively.

Battery state of charge (%)

In the formula: Q _always is the total capacity of the battery (Ah) (approximately the rated capacity of the battery); t is the charging and discharging time of the battery (h); I is the charging and discharging current (A) of the battery, I<0 when charging, and I≥ when discharging 0.

After the upper computer calculates the voltage of each battery, it makes statistics on the voltage value, counts the maximum voltage value and its corresponding battery number, the minimum voltage value and its corresponding battery number, the number of the battery with too low voltage, the number of the battery with too The highest battery number, the total voltage of the battery pack.

After the upper computer calculates the temperature of each battery pack, it makes statistics on the temperature value, counts the highest temperature value and its corresponding battery pack number, the lowest temperature value and its corresponding battery pack number, and the battery pack number with too high temperature .

By selecting the number of a single battery to be observed, the voltage, current and temperature of the battery can be observed in real time.

After the upper computer calculates the SOC and maximum temperature of each battery, it displays the value on the virtual instrument interface.

(3) LED status display

Use the digital I/O data acquisition card to collect the switch signals of each indicator light, and the on-board computer controls the corresponding indicator lights on the virtual instrument interface to turn on and off according to the collected switch signals of each indicator light. If the indicator light is on, there will be a corresponding voice prompt "xx light is on".

(4) Operation record data storage

The operation record data storage module stores some important operation data (such as vehicle speed, etc.) and fault alarm records as LabVIEW test data files (.lvm) and text files (.txt). The former file type is used to draw data curves, and the latter file type Type is used to view data records (including time and data).

Claims (5)

1. Based on virtual and digital technology combined car instrument and vehicle multi-functional information platform, its features are: the liquid crystal display is connected with the vehicle computer through the AGP slot by the graphics card, and the liquid crystal display displays the vehicle running status monitoring interface and the man-machine operation interface; the touch screen It is connected with the on-board computer through the serial port; the indicator light switch is connected with the digital I/O data acquisition card through the signal line, and the digital I/O data acquisition card is connected with the on-board computer through the PCI slot, and the digital I/O data acquisition card provides digital I/O O function, it collects: each lighting and signal indicator switch, each alarm signal indicator switch, motor fault and motor gear signal; the wheel speed sensor adopts a magnetoelectric speed sensor, which is installed on the half shaft, and communicates with the vehicle through the serial port The computer is connected to measure the rotational angular velocity of the wheel; the battery monitoring system is connected to the on-board computer through the serial port, which is used to monitor the state of charge SOC, temperature, voltage and current of the battery; the camera inputs the electrical signal to the TV card through the AV terminal, and the TV card It is connected to the on-board computer through the PCI slot, and the camera acts as a rearview mirror; the GPS receiver is connected to the on-board computer through the USB interface, and the GPS receiver receives the car positioning signal sent by the global positioning system GPS, and then uses the map matching technology to locate the car Points are depicted on the electronic map; the wireless network card is connected with the vehicle-mounted computer through the USB interface, and the wireless network card enables the vehicle-mounted computer to be connected with the Internet through the CDMA 1X network. 2. The combined vehicle instrument and vehicle-mounted multifunctional information platform based on virtual and digital technology according to claim 1, characterized in that: there are 1-7 liquid crystal displays. 3. The combined vehicle meter and vehicle-mounted multifunctional information platform based on virtual and digital technology according to claim 1, characterized in that: there is one liquid crystal display, which is divided into electronic rearview mirror area, positioning navigation area, Speedometer area, battery working status monitoring area, lighting and signal indicator area, alarm signal indicator area, program control area, the touch screen is fixed on the LCD screen; the electronic rearview mirror area displays the rear image of the car captured by the camera, In order for the driver to observe the traffic conditions behind the car; the positioning navigation area displays an electronic map, which uses the car positioning information received by the GPS receiver to depict the vehicle's running track on the electronic map; the speedometer area displays the speedometer, overspeed warning light, and reset button The one-way odometer and cumulative odometer; the battery working status monitoring area displays the battery state of charge SOC and battery temperature; the lighting and signal indicator area displays the status of the following indicators: left turn signal, right turn signal, high beam, near light, side light, front fog light, parking light, reversing light, gear position indicator light and windshield wiper indicator light; the warning signal indicator area shows the status of the following indicator lights: brake system fault light, door Not closed indicator light, seat belt not fastened indicator light, hazard warning light and motor failure light; the program control area displays the operation buttons of the following programs: electronic rearview mirror, vehicle positioning and navigation, car running record, Internet browser, MP3 Player, over-the-air TV and FM radio. 4. The combined vehicle instrument and vehicle-mounted multifunctional information platform based on virtual and digital technology according to claim 1, characterized in that: the vehicle-mounted computer is a small desktop computer or an embedded computer. 5. a kind of software system that realizes the combined car meter and vehicle-mounted multifunctional information platform based on virtual and digital technology described in claim 1, software system is mainly made up of operating system, hardware driver and application software three parts, it is characterized in that : Application software includes virtual digital vehicle instrumentation and vehicle-mounted multifunctional information platform application software, and the structure of virtual digital vehicle instrumentation and vehicle-mounted multifunctional information platform application software can be divided into main control module, event capture module, event processing module and data storage module, The main control module mainly controls and coordinates the operation of other modules in the program, The event capture module mainly monitors, identifies and reports the occurrence of external or internal events, and then notifies the main control module, and the main control module then activates the corresponding thread in the event processing module to respond to external or internal events, The event processing module is the main body of the application software function realization. It is composed of several loosely coupled function sub-modules. The function sub-modules include calls to other applications. It executes specific sub-modules triggered by external or internal events. module, to achieve a certain function, The data storage module is mainly used to store some important operating data, such as vehicle speed, mileage, driving track and fault alarm records, so as to facilitate post-event statistical analysis, fault analysis and diagnosis, The vehicle speed odometer in the event processing module, the battery monitoring system and the indicator light status display module and the operation record data storage module in the data storage module are described in detail as follows: 1) Speedometer The speedometer uses a magnetoelectric speed sensor to measure the rotational angular velocity of the wheel. The speed sensor is installed on the half shaft. When the half shaft rotates one circle, the speed sensor sends a pulse to the lower computer connected to it. The lower part of the speed odometer The machine measures the multiple n of the timing base 0.05s contained in the time interval between the rising edges of each pulse, then the pulse period T=0.05ns, the corresponding wheel speed $\mathrm{\&omega;}=\frac{1}{0.005\mathrm{no}}\&times;60=\frac{1200}{\mathrm{no}}r/\min ,$ speed ${\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0.337</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; r</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; \&omega;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0.377</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; r</span>}<span\; class="notranslate">\; \&times;</span>\frac{\mathrm{<span\; class="notranslate">\; 1200</span>}}{\mathrm{<span\; class="notranslate">\; no</span>}}\mathrm{<span\; class="notranslate">\; km</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$ Among them: r is the radius of the wheel, the unit is m, At the same time, the lower computer also counts the number of pulses sent by the speed sensor, and obtains the total number of rotations m of the wheel, then the mileage S＝2π×r×m/1000km The lower computer is connected to the serial interface RS-232 of the upper computer through the RS485-RS232 adapter, and the on-board computer as the upper computer reads the n and m values measured by the lower computer of the speedometer through the serial interface RS-232, and then press Formulas (1), (2) calculate vehicle speed and mileage, and display their values on the virtual instrument interface, The following serial port communication protocol is followed between the upper computer and the lower computer: a. Serial port settings The baud rate is 9600bps, the data bit is 8 bits, the stop bit is 1, no flow control, b. The upper computer sends instructions to the lower computer The upper computer sends the following 3 bytes to the lower computer in turn, and the delay is 10ms after each byte is sent. The first byte is the hexadecimal number 32, which is the address number of the lower computer of the speedometer, and the serial port check digit is set to Mark. The second byte is the hexadecimal number C5, which is a command for the lower computer to send data, and the serial port check digit is set to Space. The third byte is the hexadecimal number F7, which is the check code formed by the XOR of the first byte and the second byte, that is, 32 XOR C5=F7, the serial port check digit is set to Space, c. The lower computer sends data to the upper computer After the lower computer receives the above 3 bytes sent by the upper computer, it sends data n and m to the upper computer, and the data sent by the lower computer to the upper computer follows the following format: n_L-n_H-m_LL-m_LH-m_HL-m_HH-check, Among them: n_L, n_H are the 2nd and 1st bytes of the hexadecimal number corresponding to n in formula (1); m_LL, m_LH, m_HL, m_HH are the hexadecimal numbers corresponding to m in formula (2) respectively The 4th, 3rd, 2nd, and 1st bytes; the check code check is the exclusive OR of n_L, n_H, m_LL, m_LH, m_HL, and m_HH; 2) Battery monitoring system The lower computer of the battery monitoring system uses voltage sensors, current sensors and temperature sensors to measure the working voltage, current and temperature of the battery respectively, and its upper computer calculates the SOC of the battery based on the above parameters, and divides the 280 Ni-MH batteries on the vehicle into 40 groups. There are 7 cells in each group, and one lower computer for measuring voltage and temperature is installed on each group of batteries. The lower computer can measure the voltage of each battery in the battery group and the temperature of the battery group in this group. The lower computer for measuring the battery stack current, The 41 lower computers of the battery monitoring system are all connected to one network cable, which is connected to the serial port of the upper computer through the RS485-RS232 adapter. Send commands to the lower computer, and the corresponding lower computer will send the data required by the upper computer to the upper computer after receiving the command from the upper computer. The upper computer reads the voltage, current and temperature values measured by the lower computer of the battery monitoring system through the serial interface RS-232 according to the following serial communication protocol. a. Serial port settings The baud rate is 9600bps, the data bit is 8 bits, the stop bit is 1, no flow control, The upper computer sends instructions to the lower computer When measuring voltage and temperature, the upper computer sends the following 3 bytes to the lower computer in sequence, and the delay is 10ms after each byte is sent. The first byte is the address number, that is, the address number of the battery pack is 01~28 in hexadecimal, and the check digit of the serial port is set to Mark. The second byte is the command hexadecimal number C3, indicating that the lower computer is required to send voltage and temperature data, and the serial port check digit is set to Space. The third byte is the check code, which is the XOR of the first byte and the second byte, and the serial port check bit is set to Space. When measuring the current, the upper computer sends the following 3 bytes to the lower computer in sequence, with a delay of 10ms after each byte is sent. The first byte is the address number of the lower computer for current measurement, the hexadecimal number 29, and the serial port parity bit is set to Mark. The second byte is the command hexadecimal number C4, indicating that the lower computer is required to send current data, and the serial port check digit is set to Space. The third byte is the check code hexadecimal number ED, which is the XOR of the first byte and the second byte, that is, 29 XOR C4=ED, the serial port check digit is set to Space, b. The lower computer sends data to the upper computer The A/D conversion of the lower computer is 10 bits, the reference voltage is 3.3V, After the lower computer receives the above 3 bytes sent by the upper computer, it sends the data required by the upper computer to the upper computer, The data sent by the lower computer for measuring voltage and temperature to the upper computer follows the following format: the high and low voltage of the first battery in the group, ..., the high and low voltage of the seventh battery in the group, the high temperature of the battery in the group and low, The data sent by the lower computer for current measurement to the upper computer follows the following format: the current high and low bits of the battery pack, After the upper computer receives the data sent by the lower computer, it calculates the voltage, current, temperature and SOC according to the following formulas: Single battery voltage $V=\frac{V_{\mathrm{HEX}}}{1024}\&times;3.3\&times;0.5V---\left(3\right)$ battery current $I=\frac{I_{\mathrm{HEX}}}{1024}\&times;200A---\left(4\right)$ battery temperature In the formula: V _HEX , I _HEX , _THEX are the hexadecimal numbers of the voltage, current and temperature data sent by the lower computer received by the upper computer, battery state of charge In the formula: Q _is the total capacity of the battery, approximately the rated capacity of the battery, in Ah; t is the charging and discharging time of the battery, in h; I is the charging and discharging current of the battery, in A, when charging I<0, when discharging I≥0, After the upper computer calculates the voltage of each battery, it makes statistics on the voltage value, counts the maximum voltage value and its corresponding battery number, the minimum voltage value and its corresponding battery number, the number of the battery with too low voltage, the number of the battery with too High battery number, total battery voltage, After the upper computer calculates the temperature of each battery pack, it makes statistics on the temperature value, counts the highest temperature value and its corresponding battery pack number, the lowest temperature value and its corresponding battery pack number, and the battery pack number with too high temperature , By selecting the number of a single battery to be observed, the voltage, current and temperature of the battery can be observed in real time. After the upper computer calculates the SOC and maximum temperature of each battery, it displays the value on the virtual instrument interface. 3) LED status display Use the digital I/O data acquisition card to collect the switch signals of each indicator light, and the on-board computer controls the corresponding indicator lights on the virtual instrument interface to turn on and off according to the collected switch signals of each indicator light. If the indicator lights are on, there will be corresponding voice prompts "xx lights on", 4) Operation record data storage The operation record data storage module stores some important operation data and fault alarm records as LabVIEW test data files and text files. The former file type is used to draw data curves, and the latter file type is used to view data records.

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