CN101118658A - Processing method of vehicle control information of CAN bus instrument for hybrid electric bus - Google Patents

Abstract

The invention relates to a vehicle control information processing method of a CAN bus instrument for a hybrid electric bus, which belongs to the field of automotive electronic intelligent instruments. The CAN bus interface unit inside the single chip microcomputer is connected to the standard controller local area network equipped with the vehicle to receive the information of each controller in the vehicle. The information data packets sent on the CAN bus network are collected through the control of the single-chip computer program to collect the vehicle control information of the hybrid electric bus. Through calculation and inference, the comprehensive information is analyzed and the historical operation status of the vehicle is stored. , sliding bar patterns, and animation in the form of flow vector graphics; the vehicle control information of hybrid electric buses is displayed in the form of dynamic coordinate points and dynamic moving curves on the two-dimensional coordinate map. Significantly increase vehicle safety and economy. It is suitable for the complex state and large amount of information of the electromechanical hybrid electric bus.

Description

Processing method of vehicle control information of CAN bus instrument for hybrid electric bus

technical field

The invention belongs to the field of automotive electronic smart meters, and specifically relates to a full-digital smart meter which is composed of a control single-chip microcomputer, a liquid crystal screen and its control circuit, a touch screen and its control circuit, and CAN bus nodes to provide display and diagnostic tools for hybrid electric buses information processing methods.

Background technique

Electromechanical hybrid bus is a new type of bus that has been developed in recent years and has broad prospects. Its low fuel consumption, low emission, high efficiency, energy saving and environmental protection will make it a good market in large and medium cities. Hybrid electric bus is a highly complex system integrating internal combustion engine power and electric motor power. The special multi-energy management structure makes computer intelligent control very necessary. The commonly used method is that the information between the various components on the vehicle communicates through the "Controller Area Network" CAN (Controller Area Network), forming the main electronic control processor, the electronic control processor of each component, each intelligent sensor, and each intelligent execution component through The pattern of CAN interconnection. Under this pattern, timely and accurate reflection of vehicle condition information is a necessary condition for safe, efficient and economical driving of vehicles.

From the perspective of information, the whole vehicle is a local area network composed of various intelligent components through the CAN bus. The information and parameters on the network reflect the working status of the vehicle in real time, and a considerable part of the information is helpful for the driver to understand the vehicle condition (especially the multi-energy power distribution information) during driving, reasonably adjust the vehicle operating status, and maximize the use of hybrid power. The superiority of passenger cars is very important and necessary, which includes the engine in the best economical operating state, low fuel consumption, low emissions, good driving habits suitable for hybrid vehicles, reasonable maintenance, and extended component life. In addition, when abnormalities and failures occur in such a complex system, the driver (especially the inexperienced) finds out as early as possible, responds in time, and takes necessary measures to significantly increase safety and reliability. Due to the high degree of intelligence and complex information of hybrid electric buses, it is difficult to reflect it with traditional instruments, and the instrument panel will be too complicated, which is not only costly, difficult to implement, but also not convenient enough to use.

Contents of the invention

The present invention provides a method for processing vehicle control information of a CAN bus instrument used in a hybrid electric bus to solve the problem that due to the high degree of intelligence and complex information of a hybrid electric bus, it is difficult to use traditional instruments to reflect, the instrument panel will be too complicated, not only the cost is high, It is difficult to implement and not convenient enough to use. The purpose is to provide a method of downloading and processing information from CAN nodes, animation in the form of text, sliding bar patterns, and flow vector graphics through the LCD screen; displaying hybrid electric buses in various forms of dynamic coordinate points and dynamic moving curves on the two-dimensional coordinate map Control information, and a display instrument information processing method that controls the switching of display content by a touch screen. The technical scheme that the present invention takes is:

The central control single-chip microcomputer module receives the car control CAN bus information data packets sent by the engine, gearbox, motor and battery assembly controllers in the car on the CAN bus network through the CAN communication module, including engine speed, engine torque, motor speed, Real-time vehicle status information of motor torque, battery voltage, battery current, battery power and gear position;

Based on the above information obtained by the central control single-chip computer, according to the SAE J1939 protocol, the conversion of the display unit, the analysis of the multi-energy distribution status of the vehicle, the coordinate distribution of the real-time working point of the engine and the coordinate distribution of the real-time working point of the motor are calculated, and the memory is used to record the battery since the vehicle was started. The last 24 minutes historical operating status of the battery;

Through the LCD screen of the CAN bus instrument, the multi-energy distribution status is displayed in the form of a flow vector diagram; on the speed-torque two-dimensional coordinate diagram, the distribution of the immediate operating points of the engine and the distribution of the immediate operating points of the motor are displayed in the form of dynamic coordinate points; In the form of a dynamic moving curve, the battery power history curve of nearly 24 minutes is displayed on the battery power-battery working time two-dimensional coordinate graph.

The touch screen is installed on the surface of the LCD screen by sticking, the touch position is detected by the touch screen control module, and the position information is transmitted to the central control single-chip microcomputer module, combined with the current screen display content to quickly switch and select the screen display content.

We design and develop a new type of CAN bus instrument according to the specific structure of the hybrid electric bus. Adopt intelligent dot-matrix color LCD touch screen, and carry out a multi-screen display scheme for various information according to the priority and function requirements. At present, the development of domestic and international hybrid electric buses is in its infancy. This kind of domestic technology is still blank.

The vehicle control information display mode of the present invention provides functions that cannot be realized by traditional pointer instruments. The information is clear, eye-catching and intuitive. state. Significantly increase vehicle safety and economy. It is suitable for the complex state and large amount of information of the electromechanical hybrid electric bus.

Description of drawings

Figure 1: Block diagram of CAN bus instrument hardware composition for hybrid electric bus;

Figure 2: Bus interface implementation circuit;

Figure 3: CAN communication module circuit;

Figure 4: Multi-energy management screen display content and joint driving effect;

Figure 5: Multi-energy management screen display content and regenerative braking effect;

Figure 6: The display content and effect of the engine information screen;

Figure 7: The display content and effect of the motor information screen;

Figure 8: Display content and effect of the battery information screen;

Figure 9: Display content and effect of gearbox information screen.

Detailed ways

The central control single-chip microcomputer module receives the car control CAN bus information data packets sent by the engine, gearbox, motor and battery assembly controllers in the car on the CAN bus network through the CAN communication module, including engine speed, engine torque, motor speed, Real-time vehicle status information of motor torque, battery voltage, battery current, battery power and gear position;

Based on the above information obtained by the central control single-chip computer, according to the SAE J1939 protocol, the conversion of the display unit, the analysis of the multi-energy distribution status of the vehicle, the coordinate distribution of the real-time working point of the engine and the coordinate distribution of the real-time working point of the motor are calculated, and the memory is used to record the battery since the vehicle was started. The last 24 minutes historical operating status of the battery;

Through the LCD screen of the CAN bus instrument, the multi-energy distribution status is displayed in the form of a flow vector diagram; on the speed-torque two-dimensional coordinate diagram, the distribution of the immediate operating points of the engine and the distribution of the immediate operating points of the motor are displayed in the form of dynamic coordinate points; In the form of a dynamic moving curve, the battery power history curve of nearly 24 minutes is displayed on the battery power-battery working time two-dimensional coordinate graph.

The touch screen is installed on the surface of the LCD screen by sticking, the touch position is detected by the touch screen control module, and the position information is transmitted to the central control single-chip microcomputer module, combined with the current screen display content to quickly switch and select the screen display content.

To realize the above functional requirements of the present invention, the hardware design includes the following modules: a central control single-chip microcomputer module, a picture data storage module, a touch screen and its control module, a liquid crystal display and its control module, and a CAN communication module. The software includes the control program solidified in the central control single-chip microcomputer, including CAN communication processing program, LCD screen and its control processing program, hybrid electric bus energy distribution processing program, engine working condition processing program, motor working condition processing program, power battery Group status processing program, gearbox status processing program, vehicle fault record alarm program, etc.

The core control part of the present invention is to control the single-chip microcomputer module, which is connected to the standard "Controller Area Network" (Controller Area Network, referred to as CAN bus) network equipped with the vehicle through the CAN bus interface unit inside the single-chip microcomputer, and receives the engine, gearbox, and motor in the car. , The vehicle control CAN bus information data packets sent by the battery assembly controllers on the CAN bus network, the vehicle control CAN bus information data packets conform to the SAEJ1939 international standard protocol, and the control single-chip microcomputer module receives the engine, gearbox, Vehicle control CAN bus information data packets sent by each assembly controller of the motor and battery on the CAN bus network, including engine speed, engine torque, motor speed, motor torque, battery voltage, battery current, battery power and gear position in real time Vehicle status information, control the above information obtained by the single-chip computer, according to the SAEJ1939 protocol, perform display unit conversion, vehicle multi-energy distribution status analysis, engine real-time working point coordinate distribution and motor real-time working point coordinate distribution calculation, and use the memory to record since the vehicle starts The historical operating status of the battery power in the last 24 minutes since then, the LCD screen of the CAN bus instrument displays the multi-energy distribution status in the form of a flow vector diagram; the real-time engine is displayed in the form of dynamic coordinate points on the speed-torque two-dimensional coordinate diagram. The distribution of working points and the real-time working point distribution of the motor; display the history curve of the battery power in the past 24 minutes on the two-dimensional coordinate graph of battery power-battery working time in the form of a dynamic moving curve; display a fault icon to give an alarm when the vehicle is abnormal.

The CAN communication module integrated with the central single-chip microcomputer module receives CAN bus information and processes it by classification. Its hardware composition block diagram is shown in Figure 1.

MC9S12C32 single-chip microcomputer of MOTOROLA Company of the United States is selected as the control single-chip microcomputer. This instrument adopts the general bus interface technology to realize the parallel bus interface of the graphic data memory and the LCD screen. The interface schematic diagram is shown in Figure 2.

When the CAN bus instrument controller is working, the LCD screen displays the display control commands and display graphic data received through the display interface, and the information sent by the control microcontroller to the screen controller through the bus interface is divided into display control commands and display graphic data. Two categories. The transmission of the displayed graphic data is firstly read out by the output module of the control single-chip microcomputer to read the content of the image data memory, and then write the data to the interface of the screen controller.

This instrument contains touch detection components and a touch screen controller. The touch detection component is a resistive transparent touch screen with 4 output terminals installed on the surface of the LCD screen by pasting to detect the touch position and control the switching of the display content of the LCD screen. The operation of this touch analog button is fast, intuitive and simple. It does not require the driver of the vehicle to disperse too much time and energy, which is conducive to driving safety.

Various vehicle parameters (such as engine speed, power battery voltage, motor output power, etc.) used by the instrument are transmitted to the CAN bus in the form of broadcast information packets by each control unit on the vehicle. The format and identification of the information packets comply with SAE J1939 Communication protocol, the instrument receives various information packets through the CAN bus unit, and obtains relevant digital information through software analysis and processing according to the data structure defined by the communication protocol.

The CAN interface uses the CAN interface control unit module integrated in the control single-chip microcomputer, plus an integrated transceiver chip 82C250 and a protection circuit, and adopts the CAN2.0B communication format. The circuit diagram of the CAN communication module is shown in Figure 3.

The display screen used in this instrument is the 8.4-inch TFT color dot-matrix LCD screen 6448BC26-01E of NEC Company and the controller TFT6448V8-256 interfaced with the single-chip microcomputer. The LCD screen controller supports 8-bit color depth, with a total of 256 colors; it only needs to write screen control information commands to the LCD screen controller and write display data to the specified address during work. The LCD screen controller has four pages of display buffer memory, and the interface bus has a maximum parallel data bandwidth of 3M, which can independently set display pages and write pages. After writing a page in the background mode, switch the page to the display page to form animation.

The meter of this patent will be described below through the display scheme of the meter. The information processing and display scheme are important parts of the design, and the display scheme embodies the characteristics of the hybrid electric vehicle and brings into play the specialty of this instrument.

In order to reflect the characteristics of multi-energy simultaneous operation of the hybrid electric bus, the working status or performance parameters of each component are transmitted to the dead branch single-chip microcomputer through the vehicle network CAN bus of the hybrid electric bus according to the prescribed communication protocol. The meter enters the multi-energy distribution display interface immediately after the automobile engine or electric motor starts to work.

The work of the CAN bus instrument is controlled by the internal control single-chip microcomputer program, and the overall working process is as follows:

1. Receive CAN bus data

2. Analyze and process the received CAN bus data packets. If the engine speed or motor speed in the data is greater than zero, it will enter the working status display screen.

3. Check the state of the touch screen. If there is an effective system introduction, system query or system help button input, it will enter the relevant display content processing screen.

4. In the status of the working status display screen, perform the following operations cyclically:

A. Receive CAN bus data, refresh the display content and store the data content according to the content of the CAN bus data packet.

B. Check the state of the touch screen. If there is an effective control key input, enter the relevant display content processing screen.

C. If the engine speed and motor speed in the CAN bus data are both equal to zero, it will return to the state of displaying the standby screen.

D. If there is abnormal vehicle status information in the CAN bus data, the fault alarm screen will be displayed.

E. If the CAN bus data communication is abnormal (the correct data packet cannot be received within 100 milliseconds), the communication fault alarm screen will be displayed.

The multi-energy distribution display interface displays the engine icon, the motor (generator) icon, the gearbox icon, and the battery icon (as shown in Figure 4). These four icons respectively represent the corresponding parts of the whole vehicle, and their linkage relationship is based on the data information received by the CAN bus. After controlling the single-chip computer to determine the driving mode according to the output power of the engine and the current direction and size of the battery, use the control energy arrow The way the streamlines are displayed on the screen. The above four icons also act as buttons respectively. Touch the icons with your fingers to enter the detailed information display interface of the engine, motor (generator), gearbox and battery system respectively; Small icons: including small icons such as driven wheels, engine, motor, gearbox, battery, vehicle, and communication failures. Used for fault alarm function. In order to ensure that the screen displays the most important information and the driver’s most concerned information most of the time, during the display of each detailed information display interface, you can touch any position on the screen to return to the multi-energy display interface, or automatically jump to the multi-energy display interface after 10 seconds by controlling the single-chip computer. Energy management interface. When the instrument receives the vehicle fault signal transmitted on the CAN bus, the CPU first judges the fault type, then the buzzer beeps, and the corresponding fault alarm box pops up, and the red exclamation mark flashes and the corresponding fault name is displayed as a reminder The driver has failed and the source of the failure. After this state is displayed regularly for 5 seconds, if the fault is not eliminated, the fault alarm dialog box will disappear, but the fault icon will keep flashing until the fault is eliminated. The multi-energy display interface in Figure 4 is an effect diagram of the combined driving method. The multi-energy display interface in Figure 5 is an effect diagram of the regenerative braking method.

All kinds of vehicle parameters used in this instrument are transmitted to the CAN bus by means of broadcasting by each control unit according to the SAE J1939 communication protocol, and the instrument directly obtains relevant digital information from the CAN bus in the monitoring mode.

The display contents of each detailed information display interface of the instrument system are:

1. Detailed information of the engine (as shown in Figure 6): the distribution of the immediate operating points of the engine displayed in the form of two-dimensional coordinates (the abscissa is the engine speed, and the ordinate is the engine torque), and the operating points are marked at the best, second best, and relatively low. There are three areas represented by different colors; after the control microcontroller receives the engine control information through the CAN bus, it calculates the coordinates of the current working point, first blanks the display of the old working point, and then displays the new working point. (The driver can intuitively judge the working state of the engine through the area where the working point is located), and the engine power, speed, torque percentage, cooling water temperature, and throttle percentage information are displayed in the form of sliding bars. The above information is broadcasted to the CAN bus by the engine control unit.

2. Detailed information of the motor (power generation/motor): the motor used in the hybrid electric bus is a dual-purpose machine for power generation and electric motor. The detailed information of the motor is shown in Figure 7: the distribution of the real-time operating points of the motor displayed in the form of two-dimensional coordinates (the abscissa is the motor speed , the ordinate is the motor torque), and at the same time use two curves (blue) to mark the distribution range of the actual possible working points of the motor; after the control microcontroller receives the motor control information through the CAN bus, it calculates the coordinates of the current working point, first The display of the old operating point is blanked, and the new operating point is displayed. (The driver can intuitively judge the working state of the motor through the area where the working point is located), the working mode of the motor displayed in Chinese characters (namely electric, power generation, and stop); the motor power, torque percentage, and motor speed displayed in the form of a slide bar, Inverter temperature, stator temperature information. The motor information is broadcasted to the CAN bus by the motor control unit.

3. Detailed battery information (as shown in Figure 8): the control microcontroller receives the information packet sent by the battery unit controller from the CAN bus, and stores the received battery power information in the EEPROM memory integrated in the control microcontroller, sliding in two dimensions The history of battery power (SOC) in the form of a curve in the last 24 minutes (the abscissa is the historical time, and the ordinate is the battery SOC percentage), updated every 4 seconds, the curve moves to the left as time goes by, and is displayed in the form of a slider The battery voltage; the battery current (positive and negative) displayed in the form of a two-way slide bar; the charge and discharge status of the battery displayed in Chinese characters. In order to reduce the writing times of the integrated EEPROM memory in the single chip microcomputer and prolong the service life of the EEPROM, the data structure of the circular queue is adopted, and the rolling write is adopted. The battery information is broadcasted to the CAN bus by the battery control unit.

4. The detailed information of the gearbox (as shown in Figure 9): the "separation" and "combination" status of the clutch displayed in Chinese characters; the power mode (engine drive, motor drive, combined drive, motor power generation, regenerative braking) displayed in Chinese characters ); the electromechanical power mixing ratio displayed by the two-way slide bar; the vehicle speed displayed by the slide bar; the gear position information displayed by the gearbox handle position diagram, and the gearbox information is broadcasted to the CAN bus by the gearbox control unit.

Claims (2)

1. a kind of CAN bus instrument car control information processing method for hybrid electric passenger car, it is characterized in that: The central control single-chip microcomputer module receives the car control CAN bus information data packets sent by the engine, gearbox, motor and battery assembly controllers in the car on the CAN bus network through the CAN communication module, including engine speed, engine torque, motor speed, Real-time vehicle status information of motor torque, battery voltage, battery current, battery power and gear position; Based on the above information obtained by the central control single-chip computer, according to the SAE J1939 protocol, the conversion of the display unit, the analysis of the multi-energy distribution status of the vehicle, the coordinate distribution of the real-time working point of the engine and the coordinate distribution of the real-time working point of the motor are calculated, and the memory is used to record the battery since the vehicle was started. The last 24 minutes historical operating status of the battery; Through the LCD screen of the CAN bus instrument, the multi-energy distribution status is displayed in the form of a flow vector diagram; on the speed-torque two-dimensional coordinate diagram, the distribution of the immediate operating points of the engine and the distribution of the immediate operating points of the motor are displayed in the form of dynamic coordinate points; In the form of a dynamic moving curve, the battery power history curve of nearly 24 minutes is displayed on the battery power-battery working time two-dimensional coordinate graph. 2. The vehicle control information processing method of CAN bus instrument for hybrid electric passenger car as claimed in claim 1, characterized in that: the touch screen is installed on the surface of the liquid crystal display screen in a pasted mode, the touch position is detected by the touch screen control module, and the position information Send it to the central control single-chip microcomputer module, combined with the current screen display content to quickly switch and select the screen display content.

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