CN103481798A - CAN (controller area network) bus-based driving-driven distribution type control system of electric vehicle driven by hub motors - Google Patents

The invention relates to a CAN (controller area network) bus-based driving-driven distribution type controlled four-wheel-drive electric vehicle control system. A vehicle controller and four hub motor drive controllers form a driving-driven distribution type control system, the vehicle controller receives a control command of a driver to carry out differential computation of operation of the vehicle and sends the rotation speed, obtained through the computation, of each wheel to the hub motor drive controllers, and the hub motor drive controllers control motors to rotate, so that the running or braking energy recovery of the whole vehicle is realized; when the vehicle carries out a steering operation, the vehicle controller utilizes electronic differential control to replace a mechanical differential device of the traditional vehicle according to signals of a steering angle sensor to carry out the regulation on the running speed of each hub motor, so that an expected running state is realized; the CAN bus-based driving-driven distribution type controlled four-wheel-drive electric vehicle control system simplifies the driving structure of the traditional vehicle, has the advantages of light weight of the whole vehicle, flexibility in control, safety, energy-saving and environment friendliness, and is suitable for the control of electric vehicles.

The electric vehicle control system of the distributed In-wheel motor driving of MS master-slave based on the CAN bus

Technical field

The present invention relates to a kind of control system of In-wheel motor driving battery-driven car of the MS master-slave distribution control based on the CAN bus, belong to the Control of Electric Vehicles field.

Background technology

Since entering 21 century, because developing country's development of automobile industry is rapid, it is soaring that the recoverable amount of automobile is explosion type.Along with increasing rapidly of automobile pollution, the proportion of vehicle fuel consumption in whole oil production rates is also increasing, and the energy shock in the whole world is more and more obvious, and ecology environment goes from bad to worse.Meet not rely on petroleum fuel, efficiency is high and hangs down the even free of contamination new-energy automobile of pollution to become the most competitive product of future society simultaneously gradually under the overall background of the continuous progressive development of auto-industry while.The sustainable development of people and environment harmonious coexistence and global economy, make people urgently wish to seek a kind of anti-emission carburetor, high, the environmentally friendly vehicle of resource utilization, and the automobile that adopts clean energy resource will be following best selection undoubtedly.Research and development produce the new automobile of energy-saving and environmental protection, safety, change the orthodox car pattern, are the inevitable directions that automobile industry realizes sustainable development.Progress along with modern power electronics technology, automatic control technology, battery technology, the communication technology, electric machines control technology, for the research and development new-energy automobile provides strong technical guarantee, make the research and development of new-energy automobile become study hotspot and the research emphasis of future automobile industry development.

Compare with the automobile that relies on main motor to drive with traditional combustion engine, utilize the battery-driven car of In-wheel motor driving, its each wheel can carry out fast driving and braking by wheel hub motor, utilizes Electronic differential control greatly to increase the sensitieness turned to.Simultaneously, the orthodox car parts such as power-transfer clutch, diff, transmission shaft and change-speed box have structurally been deleted due to it, chassis structure is simplified relatively, complete vehicle quality significantly alleviates, reached to a great extent the lightweight of car load, simultaneously also for realizing that the chassis system high efficiency smart created favourable condition.The wheel hub drive system only need to just can realize that single or multiple wheels drive and the accurate control of braking by motor and supporting actuator, with the traditional combustion engine automobile, with the electronlmobil that adopts the drive forms such as induction motor or asynchronous dynamo, compare, this motor response is rapid, and is convenient to measure.In addition, motor directly is placed in wheel, and during power transmission, degradation of energy is almost nil, and the motor propulsive effort directly transmits by wheel, higher than other types electronlmobil type of drive execution efficiency.Like this, utilize novel electron differential scheme to drive electronlmobil to carry out differential control to wheel hub, just can realize straight-line travelling, turning driving and the acceleration and deceleration motion of vehicle.The electronlmobil of employing In-wheel motor driving is easily realized the functions such as Way of Regenerating Energy Feedback of Electricmotor car wheel.

Summary of the invention

The electronlmobil that the present invention is directed to current electric four-wheel drive has proposed a kind of control system of electric automobile of controlling effective, simple and practical, safe and reliable Web control, the problem that convenient solution four-wheel individual drive Control of Electric Vehicles is complicated, real-time is not high.

This control system comprises vehicle control device (or claiming master controller), by four In-wheel motor driving controllers, formed from controller, four (left front/right front/left back/right back) wheel hub motors, power battery pack management system, super capacitor, accelerator pedal sensor, steering angle sensor, driving switch sensor, brake switch sensor, hall position sensor, demarcation observation interface software and storage battery; Vehicle control device forms the MS master-slave distributed control network by a CAN communication port and four In-wheel motor driving controllers, it receives the control command of chaufeur, the differential that carries out automotive operation calculates, the rotating speed of each wheel of calculating is sent to the In-wheel motor driving controller, by the In-wheel motor driving controller, control electric machine rotation; Vehicle control device is communicated by letter with power battery pack management system (being called for short BMS) by a CAN communication port, receive the battery information (as parameters such as voltage, temperature, electric current, breakdown signals) of BMS transmission, at battery, do not have in situation in bad order, the vehicle control device normal operation, otherwise do not work; Vehicle control device, by another one CAN communication port and demarcation observation interface software communication, realizes that vehicle condition information shows in real time and the real-time calibration of vehicle operating parameters.

Motor drive controller adopts the special-purpose drive integrated circult IR2130 of three-phase inverter, carry out three-phase star six stateful connections, motor drive controller is selected the PIC series monolithic, output from micro controller system, in the six tunnel output pulses through conversion, wherein there is the corresponding switching valve low side in three tunnels to drive signal, then, after power gain, directly be sent to the grid source electrode of driven power device; The corresponding high-side driver signal of another three tunnel pulse, signal first carries out the current potential conversion through the level shifter of IR2130 inside, become the drive pulse signal of three road electric potential floatings, again through after output latch, drive pulse check, carry out power gain, the grid source electrode that finally is loaded into driven power device completes the driving process again.Simultaneously, motor drive controller detects from the body temperature, receives the phase signal from hall position sensor; The phase signal that utilization detects can carry out the judgement of phase sequence, obtains next commutation order constantly, drive hub motor normal rotation.

The present invention has adopted CAN bus communication mode.CAN belongs to the category of industrial field bus, than general bus, compares, and the data communication of CAN bus has advantages of stronger reliability, outstanding practicality and real-time.In view of main and subordinate node in control system is not a lot, design has adopted the Frame of standard format, and its identifier has 11, comprises respectively destination address, source address and type of message.Vehicle control device is as master controller, a given address.The priority status of four motor drive controllers is equality, and each node receiving and transmitting signal communicates according to the mode of timed sending.The data of real-time change such as rotating speed, linear velocity, the time gap of transmission is set according to the sampling frequency of data and the ability to bear of bus respectively.For the variable of event response, these variablees adopt event response to carry out data transmit-receive.For example, speed-slackening signal.As long as speed-slackening signal detected, vehicle control device sends immediately braking and controls message to four motor drive controllers.If bus arbitration is lost, after 10 milliseconds, resend, until this node obtains CAN bus right to use and completes the transmission of message.

Battery management system is protection power source effectively, plays the effect that extends battery, increases course continuation mileage.In the present invention, battery management system can be realized the effective monitoring to electrokinetic cell, by the CAN bus, sends the data that detect to ipc monitor.

The invention has the beneficial effects as follows: the Master-slave distributed control system network based on the CAN bus is succinct, safety reliable, can drive electronlmobil effectively to control in real time to the four-wheel hub.

The accompanying drawing explanation

Fig. 1 is electric vehicle control system structure principle chart of the present invention.

Fig. 2 is drive and control of electric machine diagram of circuit of the present invention.

Fig. 3 is battery-driven car differential control diagram of circuit of the present invention.

Fig. 4 is battery-driven car operation control flow chart of the present invention.

The specific embodiment

As shown in drawings: car load forms master-salve distributed control system by vehicle control device and four In-wheel motor driving controllers by the CAN bus, vehicle control device is according to accelerator pedal sensor and driving switch sensor signal, the downrange speed of Vehicle Driving Cycle is converted into to the downrange speed of each wheel, and obtain the rotating speed of four wheels according to the relation of rotating speed and linear velocity, drive respectively and control four wheel hub motors via four of front and back motor drive controller, and then drive four wheels runnings of control, realize that car load normally travels; When vehicle carries out steering operation, vehicle control device, according to the steering angle sensor signal, is implemented the mechanical differential device that Electronic differential control replaces orthodox car, carries out each wheel hub motor running velocity and regulates, and realizes the expection running state; Slow down, slide or stop while travelling, according to the brake switch sensor signal, by gear, regulates and carry out the braking energy recovery, by the power storage of recovery in super capacitor.

In the present invention, drive and control of electric machine is the basic guarantee that battery-driven car travels, and speed is controlled in real time as control object, and it drives control flow to see Fig. 2, by following step, is undertaken: the configuration of PIC port resource, PWM function setting; Detect armature position when static, judge current phase place; According to driver command, vehicle control device sends and advances or the signal that falls back to four motor drive controllers, and driving governor receives instruction; Open the electric machine control enable signal, read the location information of any time three-phase coil, the judgement phase sequence, calculate current rotating speed according to three-phase position signal, to vehicle control device, sends present speed information simultaneously; According to the target setting rotating speed, carry out the adjustment of rotational speed of PID, regulate electric current loop.The corresponding rotating speed of target that four wheels of car load will receive from the CAN bus, as controlling target, is regulated the actual speed quick adjustment of four wheels to rotating speed of target by driver module.

In the present invention, Electronic differential control is the guarantee that vehicle can normally move, and the quality of differential control directly has influence on driving performance.On smooth-going forthright, directly by the given PID of acceleration pedal, regulate and can normally travel.During turning operation, by bearing circle, carry out the deflection that turns to of expection and the steering angle signal is passed to vehicle control device, vehicle control device calculates the rotating speed of target of four wheels by differential, and diagram of circuit as shown in Figure 3.

Braking energy reclaims: electronlmobil in motion, generally has several operating modes such as startup, acceleration, deceleration, parking.According to the judgement of different operating modes, electric automobile energy is controlled and also is not quite similar.When running into brake snub or taxiing operation, vehicle control device is opened the regenerative brake loop, and motor driver makes wheel hub motor carry out the recovery of braking energy in generator mode, all is stored in super capacitor.During emergency braking, mechanical braking acts on simultaneously, with support vehicles safety.

Demarcate observation interface software and communicate by letter and carry out monitoring and the demarcation that car load is controlled parameter by CAN, detect the real-time parameter variable situation of electrokinetic cell simultaneously.

The present invention is not limited to above-described embodiment, and equivalent concepts or change in any technical scope disclosed in the present invention, all classify protection scope of the present invention as.

1. the electric vehicle control system of the master-salve distributed In-wheel motor driving based on the CAN bus, it is characterized in that: control system is by four of front and back wheel hub motor, four In-wheel motor driving controllers, vehicle control device, power battery pack management system, super capacitor, accelerator pedal sensor, the brake switch sensor, steering angle sensor, hall position sensor, the driving switch sensor, demarcate and detect interface software and storage battery composition, vehicle control device forms the MS master-slave distributed control network by a CAN communication port and four In-wheel motor driving controllers, it receives the control command of chaufeur, the differential that carries out automotive operation calculates, the rotating speed of each wheel of calculating is sent to the In-wheel motor driving controller, control electric machine rotation by the In-wheel motor driving controller, it is communicated by letter with power battery pack management system by a CAN communication port, receives the battery information of BMS transmission, at battery, do not have in situation in bad order, and the vehicle control device normal operation, otherwise do not work, vehicle control device, by another one CAN communication port and demarcation observation interface software communication, realizes that vehicle condition information shows in real time and the real-time calibration of vehicle operating parameters.