CN102848990A

CN102848990A - Electronic control network of automobile

Info

Publication number: CN102848990A
Application number: CN 201110175532
Authority: CN
Inventors: 张骁懿
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-06-28
Filing date: 2011-06-28
Publication date: 2013-01-02

Abstract

The invention provides an electronic control network of an automobile, which relates to an improvement of the conventional electronic control network of an automobile, is more accurate and is capable of solving network conflict and time delay of a vehicle-mounted CAN (Controller Area Network) bus. The electronic control network is designed with three electronic control units (ECUs) of the automobile, namely, an anti-locking brake system (ABS), an electronic power-assisted steering (EPS) unit and an automobile body control unit, and the ECUs form high, medium and low speed nodes of the CAN bus so as to form a control network; and the core of the electronic control network is a software module which is mainly composed of a system initializing module, a start self-checking module, a main control module, a data acquisition module, a data processing module, a reference automobile speed calculating module, a road surface identifying module, an automobile movement state identifying module, a control decision and execution mechanism acting module, a failure diagnosing module and a communication module, and the modules are uniformly dispatched in real time and distributed with operation time by the main control module according to a task management mechanism and exchange data and signals with one another.

Description

A kind of Vehicle Electronic Control network

Technical field:

The present invention relates to the improvement of Vehicle Electronic Control network.

Background technology:

Abroad, many international car companys just actively are devoted to research and the application of vehicle electronics network technology as far back as the eighties.From 1992, Mercedes Benz began to use the CAN technology at their coach luxury coach.The CAN bus since it is born, the attention that is subject to industry member with its unique design philosophy, good performance and high reliability.Abroad, US and European especially, CAN has been widely used in the fields such as automobile, train, steamer, robot, machine manufacture, numerically-controlled machine tool, textile machine, medical machinery, farm machinery, sensor and instrument and meter for automation.Although the CAN agreement has had the history in 20 years nearly, it still is among the improvement.

The buses such as CAN have obtained using more widely at home, are applied in large quantities industrial or agricultural monitoring, power plant's observing and controlling, fire alarm, Substation control, coal comprehensively monitoring etc.A lot of universities and colleges and R﹠D institution also drop into a large amount of manpowers and fund research and development fieldbus, the especially research and development of CAN bussing technique.

The domestic CAN bus of having paid close attention to very early, the application on the Vehicle Electronic Control field also increase gradually.From the new model of external introduction, all equipped the vehicle electronics network of different scales recent years, such as the trendy imperial crown of Passat, Audi, Toyota of popular company, Chang'an Ford Carnival etc.Along with the automobile control complexity of function and increasing of electronics package, utilizing the CAN network is the inexorable trend of vehicle electronics development.

Now, although the application of CAN bus on the Vehicle Electronic Control field is closely very ripe, but because the conflict of network data or the time delay of communication, make control command often can not be transferred in time the ECU (Electrical Control Unit) of actuating unit by electric wire, although this time delay only has several milliseconds, might be because these several milliseconds cause a traffic accident.

Summary of the invention:

The present invention is exactly for the problems referred to above, provides a kind of vehicle-mounted CAN bus network conflict, time delay of can solving, more accurate Vehicle Electronic Control network.

For solving the problems of the technologies described above, the present invention is achieved in that

At hardware aspect, take treater as core, three cover vehicle electronic control units (ECU) have been designed, be ABS (Anti-lock Braking System) unit (ABS), electronic power assist steering unit (EPS), and vehicle body control unit, utilize them to form the high, medium and low fast node of CAN bus, consist of the control network; Electronic control unit (ECU), be ABS (Anti-lock Braking System) unit (ABS), electronic power assist steering unit (EPS), and the integrated system of the integrated rear formation of vehicle body control unit, core is software module, software module is mainly by system initialization module, start selftest module, main control module, data acquisition module, data processing module, the reference speed computing module, the road surface identification module, the state of motion of vehicle identification module, control decision and actuating unit action module, fault diagnosis module, several most of compositions such as communication module, each module is carried out United Dispatching by main control module in real time by task management mechanism, distribute time of run, carry out the exchange of data and signal.

Beneficial effect of the present invention:

Realized the network architecture rationalization, the node type diversification, the interstitial content maximization, system is mainly by ABS (Anti-lock Braking System) unit (ABS), electronic power assist steering unit (EPS), vehicle body control unit three parts consist of, substantially satisfied the Vehicle Electronic Control network architecture, not only has different data transmission rates (at a high speed, middling speed, low speed), and node type is also very abundant, comprise multi-way switching values, analog quantity, impulse singla etc., respectively the fault loop signal in the simulates real real vehicle, the solenoid control signal, the electronic striking signal, the car door control signal, the car light control signal, the oil pressure feedback signal, vehicle wheel rotational speed detection signal etc.; Vehicle body control unit, except self as the independent CAN bus node, it has also played the part of the role of bridge, makes three subelements can realize mutual data transmission by it; Whole system is monitored by the upper computer software of voluntarily establishment.

Description of drawings:

Fig. 1 is entire block diagram of the present invention;

Fig. 2 is ABS control principle drawing of the present invention;

Fig. 3 is EPS control principle drawing of the present invention;

Fig. 4 is software architecture diagram of the present invention.

The specific embodiment:

As a kind of preferred version, the treater that the present invention adopts is the MC9S12DP256 treater of Si Kaer company development.

The implementation procedure of the each several part unit of vehicle electronic control unit (ECU):

1, ABS (anti-skid brake system) unit: automobile anti-lock braking system processed is the automobile active safety parts, it is a kind of active safety feature that prevents the braking procedure wheel lockup, it can guarantee validity, safety and the direction controllability of automobile in braking procedure, shorten stopping distance, guarantee traffic safety.The ABS system passes through the slippage situation on sensor senses wheel and road surface in braking procedure, judged by ECU (Electrical Control Unit), and the action device that forms by electromagnetic valve, adjust the size of braking force, make the tyre skidding rate remain on a desirable scope, larger vertical braking and the ability of anti-side direction external force are arranged when guaranteeing car brakeing, prevent that contingent trailing wheel from breakking away, whipping, the front-wheel sideslip, the direction of raising automobile in braking procedure stablized the ability with handling maneuver, and can improve adhesion coefficient utilization, shorten stopping distance, reduce wear on tyres.

The ABS basic functional principle is to remove each instantaneous state of kinematic motion of perception brake wheel by wheel speed sensors, and according to its state of kinematic motion size of regulating brake lock torque correspondingly, avoids the locking of wheel, thereby be a closed loop brake system.Its control principle is seen Fig. 3;

2, EPS (electronic power assist steering system) unit: the electronic power assist steering system relies on the physical efficiency of chaufeur and carry out motor turning under other energy helps.Power steering was in the past multiplex in large-scale, heavy motor vehicle, and along with the increase of engine behind front wheel forward drive vehicle, servo steering device has become the standard facility of car.Along with day by day universal on automobile of power steering system, no longer be merely in order to alleviate operating effort to the requirement of its performance, but can produce corresponding, suitable turning force according to the variation of the speed of a motor vehicle and driving conditions.Desirable power steering system should can provide enough power-assisteds when dead ship condition, make pivot stud easy, and power-assisted reduces gradually when the speed of a motor vehicle increases, and then answers non helping hand when entering fast state, allows chaufeur that certain " road feel " arranged.This power steering swivel system of will seeking help can according to the variation of automobile running condition, be carried out control to the size of power-assisted.

The formation of EPS is as shown in Figure 4: it is comprised of manual steering gear, electrical motor, control unit (ECU), power-transfer clutch, torque sensor and car speed sensor etc.When the steering dish turns to, the vehicle speed signal that the torque signal that control unit produces according to torque sensor, car speed sensor produce and certain assist characteristic rule, amplitude and the direction of the electric current of control electrical motor, thus form suitable power steering.The moment of torsion of electrical motor output is amplified by speed reduction gearing, and by conveyer in universal-joint, the steering box output torque is sent to tooth bar, thereby provides booster torquemoment to turning to.The signal source of booster torquemoment comprises: torque sensor, steering angle sensor and car speed sensor etc.;

3, Body Control (bridge) unit: body control system is as a node in the CAN bus network, and itself can bear multiple load, and such as car light, vehicle window etc. enriched contained general content in the network.Because ABS is set to the high-speed CAN bus network, and EPS is set to middling speed CAN bus network, and different owing to communication speed between the two, causes and can't communicate by letter, so just also need body control system to play the part of the wherein role of bridge, realize triangular connection.

Vehicle body control unit is comprised of following subelement: illumination and signalling apparatus, automatically controlled central door lock control system, automatically controlled act window control system, CAN bus interface circuit.

Carry out the planning of network based on the method that the electrical control unit design of bus can adopt CAN bus and LIN bus to combine, realize the vehicle body of foregoing description and the function of car door.Wherein there is the part of requirement can adopt low speed CAN bus to carry out network design to the speed of the transmission of data, then can adopts the LIN bus to design to the transfer rate part by specific (special) requirements useless.Adopt above-mentioned bus mode design will change the implementation of controlling in the car fully, greatly simplified the Design and manufacture technique of vehicle body, the cost that reduces maintenance and make.

Concrete software flow design is as follows:

1. system initialization module.System powers on, and each unit enters initial phase.Comprise initialization of variable (radius of wheel size, the settings of motor target current etc.), (all Reflectors reset in each location mode initialization, lock, car light, vehicle window reset etc.), each functional module initialization of treater (system clock initialization, each port initialization, the timer initialization, each interrupts initialization, the initialization of CAN bus controller, the SPI module initialization, the SCI module initialization, PWM module initialization, AD module initialization etc.) and the initialization of CANl inkII and CANbrige communication module.

2. system starts selftest module.Whether in order to make system safety operation, system is resetting and initialization will be carried out self check after complete, and the crucial soft and hardware of system is partly carried out Static Detection, normal with the soft and hardware work of judging system.During System self-test, warning lamp will be lighted automatically, if having fault in the electronic control package discovery system, the failure warning lantern festival continues to light; If have fault in the not discovery system, after process of self-test finished, warning lamp is the meeting automatic distinguishing after 1.5 seconds, and the expression integrated system is in normal operating condition.

3. main control module.Main control module is the control main program of system, sees Fig. 6 .18 wire frame part.Main control module self is done unlimited circulation, calls continuously fault diagnosis module, data processing module, reference speed computing module, road surface identification module and state of motion of vehicle identification module, carries out in real time the judgement of state of motion of vehicle and external environment.

4. data acquisition interrupt service routine.Data acquisition module is finished by the Interruption service routine.The structural shape that integrated system adopts data acquisition to separate with master control program.Because ABS electromagnetic valve action response time is not less than 7ms usually, adds the mechanical hysteresis of brake system, traditional data acquisition and control cycle can not be lower than the electromagnetic valve action response time usually.More convenient and accurate for data are processed, improving the data sampling frequency is one of a kind of actv. means, and therefore, integrated system has adopted the Interruption data acquisition program in 3ms cycle.In order to satisfy the needs of integrated system, the data owner that gathers at present will comprise: four vehicle speed signal, four wheel speed signals, four fuel injection pressure signals, torque signal etc.Consider that data acquisition module belongs to Real time capable module, higher to requirement of real-time, so when design software, utilize as much as possible hardware resource, reduce the holding time of MCU.MC9S12DP256 has 8 Enhanced Timers (ECT), each timer can be selected to compare as input capture or output by software, wherein there are four with input maintenance energy disperser, when impulse singla positive rise (being chosen as falling edge) comes then, MCU automatically puts into the time value in the input capture register and keeps energy disperser, simultaneously the current time value of master timer is put into the input capture register, therefore relatively easily realize the collection of four speed of a motor vehicle, wheel speed signal based on survey Zhou Fake.Fuel injection pressure signal and torque signal all are analog signals, and their collection is finished automatically by the AD modular converter of MC9S12DP256 inside.Be provided with the complete interruption of analog signal AD conversion, in interrupt handling routine, store transformation result.

5. control execution module.Mainly refer to the actuating units such as electromagnetic valve, relay, motor are controlled accordingly, to finish each subelement control task, reach expection control index.

Claims

1. Vehicle Electronic Control network, it is characterized in that at hardware aspect, take treater as core, three cover vehicle electronic control units (ECU) have been designed, be ABS (Anti-lock Braking System) unit (ABS), electronic power assist steering unit (EPS), and vehicle body control unit, utilize them to form the high, medium and low fast node of CAN bus, consist of the control network; Electronic control unit (ECU), be ABS (Anti-lock Braking System) unit (ABS), electronic power assist steering unit (EPS), and the integrated system of the integrated rear formation of vehicle body control unit, core is software module, software module is mainly by system initialization module, start selftest module, main control module, data acquisition module, data processing module, the reference speed computing module, the road surface identification module, the state of motion of vehicle identification module, control decision and actuating unit action module, fault diagnosis module, several most of compositions such as communication module, each module is carried out United Dispatching by main control module in real time by task management mechanism, distribute time of run, carry out the exchange of data and signal.

2. a kind of Vehicle Electronic Control network according to claim 1 is characterized in that treater is the MC9S12DP256 treater of Si Kaer company development.