Research on the control strategy of the hottest IS

Research on ISAD diesel engine control strategy

Abstract: the characteristics of domestic and foreign hybrid electric vehicle control strategies are analyzed. According to the characteristics of various components of ISAD system and the operating conditions of vehicle diesel engine, different control strategies are formulated from the perspective of fuel economy and reasonable cooperation of power source according to the operating conditions of the whole vehicle, with SOC value, vehicle speed, power and accelerator pedal position as the main control parameters, In addition, the implementation of the wear representation strategy under different working conditions is described and analyzed in detail

key words: ISAD, diesel engine, control strategy

I. preface

the Integrated Starter Alternator Damper (ISAD) automotive power assist system is suitable for urban public transportation and large-scale long-distance transport vehicles that start frequently. The two on-board power sources of ISAD diesel engine work in coordination with each other, and a good control strategy is needed to control the working condition and power output of diesel engine and motor. At present, there are mainly two control strategies

(1) directly express the optimization objective as a function of system state variables and control variables, such as Chrysler Dodge fearless ESX and other vehicles; Honda Insight and Nissan hybrid adopt the control strategy with cost and fuel economy as the main parameters; Reference [1] proposed a control strategy for optimizing the torque and power distribution of diesel engines and motors (generators); In addition, Continental AG of Germany proposed the optimization technology of motor rated power required for calibration according to the minimum fuel quantity; Domestic universities are also studying the control strategy with wheel power as the main parameter

(2) the energy (power) loss of the whole system is indirectly obtained by calculating the efficiency of each component under the current driving conditions, such as the speed control strategy first proposed in literature [2]; The control strategy with the throttle position as the parameter studied by Chongqing University; And the control strategy with SOC value as the main parameter, which is widely used in hybrid electric vehicles at present

II. ISAD diesel engine and control system

isad system is composed of engine, motor and battery. As a motor, it can be used not only for power assistance, but also as a generator to provide electric energy to batteries and other auxiliary equipment

isad diesel engine starts, the motor helps to drive the diesel engine to idle speed in a very short time; When accelerating (overtaking) or climbing, the motor and diesel engine are driven together, so that the vehicle has better power and fuel economy; In low load operation, the diesel engine works in the high-performance area to ensure reliability and economy, and drives the vehicle and generator at the same time; When braking and taxiing, the inertia drive generator of the car is used to charge the battery to realize energy feedback

through the control technology between diesel engine and motor, the high-efficiency ISAD system can realize the reasonable and effective distribution of energy between diesel engine and ISAD on the premise of meeting the dynamic performance and other technical performance of the vehicle, so as to maximize the efficiency of the whole vehicle system and obtain the best fuel economy and the lowest emission of the whole vehicle. According to the requirements of CA6110 supercharged diesel engine and vehicle operation, the software of control system and control strategy is developed. Figure 1 is the schematic diagram of control system principle. The working principle of the control system is as follows

Figure 1 control system even if Hua Tuo is reincarnated, there are only two medical methods: Mapei powder and bone scraping therapy poison step by step or innovative upgrading principle diagram

(1) ISAD controller obtains diesel engine water temperature through high-precision thermistor sensor, and Hall sensor obtains diesel engine speed and speed signals to distinguish the working state of diesel engine and vehicle, The subjective desire of the driver is judged by signals such as the accelerator pedal position sensor

(2) ECU receives the battery and motor information, obtains the current operating point of each module, and estimates the maximum output power of the motor and the maximum output power of the diesel engine at the current speed

(3) ECU determines the running state of the whole vehicle and estimates the driving power demand by receiving the information provided by the driver

(4) ECU determines the power of the motor through the decision-making and calculation of the control strategy. According to the test data of the diesel engine, obtain the three-dimensional map data chart of the throttle position, speed and output power of the diesel engine, and then determine the running state of the motor according to the speed and power of the diesel engine

(5) ECU executes the operation of the motor according to the power of the motor. After the output torque of diesel engine and motor is coupled by torque, the transmission system drives the wheels, so as to control the normal operation of the whole vehicle

(6) the control parameters are mainly throttle lever position, diesel engine speed, vehicle speed, exhaust temperature, accelerator pedal position and other parameters

isad controller can meet the driving requirements of the whole vehicle. The controller can work within the temperature range of -40 ° C ~ 70 ° C, and can provide can bus communication with other vehicle systems

III. vehicle requirements and control strategy

(I) vehicle requirements and motor parameters

vehicle requirements when the speed of the diesel engine is less than 1500r/min, increase the output torque of the vehicle through ISAD, make up for the lack of low-speed torque of the supercharged diesel engine, play a role of assistance, reduce the smoke of the supercharged diesel engine, and improve the acceleration performance of the vehicle. After using ISAD, when the speed is less than 1500r/min, the maximum output power compensation value of the diesel engine is 10kW, and the maximum torque compensation value is 100N · M

the motor is a 16 level permanent magnet synchronous motor, which adopts field weakening control technology. The working voltage of the motor is 36V, the rated current is 300A, and the rated speed is 800r/min; The output power of the motor is 10kW, and the maximum output torque is 100N · M. as a generator, the output power is 3KW, the rated voltage is 42V, and the charging current is 10 ~ 20A

(II) control strategy

according to the working characteristics of the engine and the operating conditions of the vehicle, put forward the control strategy of giving consideration to the above requirements of the diesel engine, motor and battery, make full use of the high-efficiency area of the diesel engine and battery, so as to achieve the highest overall efficiency, realize the reasonable and effective distribution of energy between the diesel engine and motor, maximize the efficiency of the whole vehicle system, and obtain the best fuel economy of the whole vehicle Minimum emissions and smooth driving performance

1. control strategy under stable working conditions

when the SOC of the battery is in the normal working area (soc>80%), the ISAD system is in stable working conditions. The starting point of the control strategy is to make the diesel engine work in its economic mode as much as possible. The working condition of ISAD is mainly judged by the driver's subjective desire, accelerator pedal position, vehicle speed, engine speed and other parameters, and the control strategy aiming at fuel economy is adopted

when the car is running at low speed, the motor works as a motor. Near the 25% - 33% opening range of the accelerator pedal, the ISAD controller judges the driver's subjective desire according to the change rate of the accelerator pedal. If the change rate is greater than a certain value, it indicates that the driver wants to increase the speed. At this time, what preparations should be done before ISAD as a motor adhesive stripping force tester is installed? Jinan new era Gold Testing Instrument Co., Ltd. today provides you with the correct method: work and play a helping role. With the increase of the accelerator pedal angle, before reaching a larger position, when the speed of the diesel engine reaches a certain set value, in the change process of this area, if the output torque of the diesel engine reaches a certain value, and the vehicle speed also reaches the driver's expected value, for example, when the speed of the diesel engine reaches 1500r/min and the vehicle speed reaches 45km/h, the ECU sends a control command to the motor, The motor completes the transformation from maximum power output to maximum power generation. When the opening of the accelerator pedal is greater than 60%, the speed of the diesel engine is greater than 1600r/min, and the change rate of the accelerator pedal is small, it shows that the torque output by the diesel engine can meet the requirements of vehicle operation. At this time, part of the surplus power of the diesel engine is transmitted to ISAD, which is in the generator working mode to charge the battery

when the opening of the accelerator pedal is in the range of 60% - 80%, the speed of the diesel engine is greater than 1800r/min, the speed is greater than 60km/h, and the change rate of the accelerator pedal is small, the diesel engine continues to provide driving power for the vehicle. The motor does not participate in power assistance and continues to work as a generator

if the opening of the accelerator pedal is greater than 80%, the speed of the diesel engine is greater than 1800r/min, and the speed is greater than 70km/h, and the change rate of the accelerator pedal is large, it indicates that the driver's subjective desire is to increase the speed. At this time, ISAD works as an electric motor to participate in the supply of driving energy, and the electric motor and the diesel engine jointly provide vehicle driving power

during driving, for small brake pedal opening (30%), mechanical braking is mainly used, supplemented by motor braking, so as to achieve the purpose of safe, effective and fast braking

2. control strategy under non-stationary working conditions

multi energy control under stationary working conditions mainly considers whether there is serious wear or failure of internal components of vehicle drive, but does not consider the problem that battery SOC exceeds its working area. The control strategy under non-stationary working conditions fully considers the impact of battery SOC changes on multi-energy management under different vehicle conditions (vehicle speed and road conditions). Combined with various working conditions under stable working conditions, ECU gives timely and reasonable response to the transmitted battery performance parameters, issues control instructions, and adopts the control strategy with SOC as the main parameter

when battery SOC