CN101788599A - Current acquisition system fault detection and processing method for mild hybrid electric vehicle - Google Patents

Abstract

The invention provides a current acquisition system fault detection and processing method for a mild hybrid electric vehicle, which includes that: when the high voltage power of the hybrid power system is conducted, a HCU acquires the current signals transmitted by a BCU and a IPU through a CAN bus, and judges if any problem occurs to the current acquisition after filtering and calculation, and then the HCU starts the corresponding fault processing program to monitor and process the current signals of the whole system in system level, thereby avoiding the damage of key parts such as a power battery due to the current signal problems.

Description

A kind of moderate hybrid vehicle current acquisition system fault detect and disposal route

Technical field

The invention belongs to moderate hybrid vehicle fault detection technique field, be specifically related to detection and fault handling the current acquisition system fault.

Background technology

Because petroleum resources and environmental problem, more and more countries, more and more enterprises are recognized the automobile that must seek a kind of alternative conventional gasoline, diesel-engine vehicles, pure electric automobile is considered to ultimate solution.But the situation of reality is that the energy density of the key components and parts electrokinetic cell of pure electric automobile is low, has seriously limited the continual mileage of pure electric automobile.And the moderate hybrid vehicle has adopted engine and motor dual dynamic, has fundamentally overcome the problem of the continual mileage that causes because of the battery technology bottleneck.And on problems such as oil consumption, discharging, orthodox car is greatly improved again.

Because the hybrid vehicle orthodox car has increased parts such as electrokinetic cell, ISG motor, DCDC, and the SOC of electrokinetic cell calculates and depends critically upon the electric current that battery management system collects, and when HCU calculates ISG motor demand torque, the DCDC output power also is the reference conditions an of necessity, so guarantee that the electric current that current sensor collects is accurately extremely important for hybrid vehicle.

Current, other motor vehicle driven by mixed power is mainly by strengthening that the method for the quality control of current sensor Acquisition Circuit is guaranteed that to greatest extent the electric current that current sensor collects is accurate.But this method can not be diagnosed the electric current that current sensor collects, and is unfavorable for the protection to key components and partss such as electrokinetic cells.

Summary of the invention

Technical matters solved by the invention provides the method for a kind of moderate hybrid vehicle current acquisition system fault detect and processing, entire car controller is received the input current (IPU_CURRENT) of the ISG controller that the ISG electric machine controller sends by the CAN bus interface, the electric current (DCDC_CURRENT) of the input DCDC that electrokinetic cell controller (BCU) sends and the output current (BCU_CURRENT) of electrokinetic cell, calculate the absolute value of (IPU_CURRENT+DCDC_CURRENT-BCU_CURRENT) after the filtering, if absolute value surpasses corresponding restriction, entire car controller enters corresponding exception handles, thereby on system level, the current signal of total system is monitored and handled, thereby avoid because the current signal problem causes key components and parts damages such as electrokinetic cell.

For realizing above purpose, the present invention adopts following control method:

After the high-voltage relay adhesive in the electrokinetic cell bag, the conducting of car load high pressure, this moment, the current failure measuring ability activated.Current failure detection module one-period carries out calculating after the Filtering Processing to the current signal that ISG controller and electrokinetic cell controller send over, the absolute value that has obtained difference between current after calculating surpasses permission during the time greater than setting value continuously, and car load enters corresponding exception handles.

The step of described method is as follows:

According to the processing requirements of CAN communication network to current signal, with BCU, the CAN communication frame that IPU sends current signal is set at A, BCU is that the CAN communication frame of A sends to HCU with electrokinetic cell output current, DCDC input current by the cycle, and IPU is that the CAN communication frame of A sends to HCU with the input current of ISG motor by the cycle;

HCU carries out Filtering Processing to each signal after receiving the current signal that BCU, IPU send over, and identical to each signal filtering processing mode, the Filtering Processing formula is:,

y(n)＝K*(u(n)-y(n-1))+y(n-1)

Wherein u (n) expression HCU receives current current signal, and y (n) expression is through current current signal after the Filtering Processing, and y (n-1) expression is through the current signal of A before the time after the Filtering Processing, K=0.1;

HCU carries out following calculating to current signal after treatment:

At first, on duty with reference factor 0.2 with what obtain after the addition with filtered ISG input current and the addition of DCDC input current, if the value after multiplying each other is greater than reference value 5, the value after then limits value equals to multiply each other, otherwise limits value equals reference value;

Before fault is judged, the affirmation time B of elder generation's failure definition, B must be greater than A and must be greater than IPU, the BCU filtering time to current signal, in general B is more than or equal to 5A, smaller or equal to 10A, if ISG input current and the addition of DCDC input current are added behind the limits value less than the electrokinetic cell output current, perhaps ISG input current and the addition of DCDC input current are reduced behind the limits value greater than the electrokinetic cell output current again, and surpass B continuous time, HCU just judges that current signal goes wrong, and just can be set to 1 by current failure zone bit E_I_;

At E_I is 1 o'clock, and the fault processing module of HCU inside then enters second level exception handles, and in this exception handles, HCU lights trouble light MIL, and the demand torque to the ISG motor carries out following processing simultaneously:

Charging moment of torsion＜=DCDC the input current of demand multiply by electrokinetic cell voltage

The booster torquemoment of demand=0.

As shown from the above technical solution, after the conducting of car load high-tension electricity, system begins to carry out current failure and detects, when the electric current difference continuous surpass setting value after a period of time, system thinks that problem has appearred in current signal, this moment, system will limit the power that discharges and recharges of ISG motor, avoided because the electrokinetic cell SOC error of calculation that causes of current signal problem is excessive, thereby caused electrokinetic cell to be damaged electrokinetic cell by excessive discharging and recharging.

Description of drawings

Fig. 1: current detecting system synoptic diagram of the present invention

Fig. 2: current detecting system fault detect process flow diagram of the present invention

Embodiment:

Moderate hybrid vehicle current detecting system fault detect disclosed by the invention and disposal route, this method is after the conducting of hybrid power system high-tension electricity, entire car controller obtains the current signal that BCU, IPU send over from the CAN bus, after Filtering Processing, calculate the back and judge whether current acquisition has problems, can avoid like this because the electrokinetic cell that the current acquisition problem causes damages.

Concrete control method below is described:

BCU by the cycle be the CAN communication frame of 10ms with the electrokinetic cell output current, the DCDC input current sends to HCU, IPU is that the CAN communication frame of 10ms sends to HCU with the input current of ISG motor by the cycle.

HCU receives BCU, behind the current signal that IPU sends over, each signal is carried out Filtering Processing, and identical to each signal filtering processing mode, the Filtering Processing formula is:,

y(n)＝K*(u(n)-y(n-1))+y(n-1)

Wherein u (n) expression HCU receives current current signal, and y (n) expression is through current current signal after the Filtering Processing, and y (n-1) represents through the current signal before the 10ms after the Filtering Processing, K=0.1

HCU carries out following calculating to current signal after treatment:

At first with filtered ISG input current (IPU_Current) and DCDC input current (DCDC_Current) addition, the value Sum_Current that obtains after the addition be multiply by Factor=0.2, if the value Mult_Sum_Current after multiplying each other is greater than reference value Ref_Val=5 then limits value Lim_Val equals Mult_Sum_Current, otherwise Lim_Val equals Ref_Val.

If Sum_Current+Lim_Val＜BCU_Current, perhaps Sum_Current-Lim_Val＞BCU_Current, and continuous time surpasses 100ms, and HCU just judges that current signal goes wrong, just can be set to 1 by current failure zone bit E_I_.

At E_I is 1 o'clock, and the fault processing module of HCU inside can enter 2 grades of exception handles, and in this exception handles, HCU lights the MIL lamp, and the demand torque to the ISG motor carries out following processing simultaneously:

Charging moment of torsion＜=the DCDC_Current*BCU_Voltage of demand (electrokinetic cell output voltage)

The booster torquemoment of demand=0

The present invention discharges and recharges moment of torsion by restriction ISG motor, can guarantee that vehicle can also drive in the limping mode, but remind driver's vehicle fault to occur by the MIL lamp simultaneously, need keep in repair.So just avoided because thereby the current signal collection goes wrong and causes SOC to calculate inaccurately further causing electrokinetic cell to be overcharged or discharge and the electrokinetic cell that causes damages from two aspects.

Claims (1)

1. moderate hybrid vehicle current acquisition system fault detect and disposal route, described method is after the conducting of hybrid power system high-tension electricity, entire car controller HCU obtains the current signal that battery management system BCU, electric machine controller IPU send over from the CAN bus, after Filtering Processing, calculate the back and judge whether current acquisition has problems, avoid thus because the electrokinetic cell that the current acquisition problem causes damages;

The step of described method is as follows:

According to the processing requirements of CAN communication network to current signal, with BCU, the CAN communication frame that IPU sends current signal is set at A, BCU is that the CAN communication frame of A sends to HCU with electrokinetic cell output current, DCDC input current by the cycle, and IPU is that the CAN communication frame of A sends to HCU with the input current of ISG motor by the cycle;

HCU carries out Filtering Processing to each signal after receiving the current signal that BCU, IPU send over, and identical to each signal filtering processing mode, the Filtering Processing formula is:,

y(n)＝K*(u(n)-y(n-1))+y(n-1)

Wherein u (n) expression HCU receives current current signal, and y (n) expression is through current current signal after the Filtering Processing, and y (n-1) expression is through the current signal of A before the time after the Filtering Processing, K=0.1;

HCU carries out following calculating to current signal after treatment:

At first, on duty with reference factor 0.2 with what obtain after the addition with filtered ISG input current and the addition of DCDC input current, if the value after multiplying each other is greater than reference value 5, the value after then limits value equals to multiply each other, otherwise limits value equals reference value;

Before fault is judged, the affirmation time B of elder generation's failure definition, B must be greater than A and must be greater than IPU, the BCU filtering time to current signal, in general B is more than or equal to 5A, smaller or equal to 10A, if ISG input current and the addition of DCDC input current are added behind the limits value less than the electrokinetic cell output current, perhaps ISG input current and the addition of DCDC input current are reduced behind the limits value greater than the electrokinetic cell output current again, and surpass B continuous time, HCU just judges that current signal goes wrong, and just can be set to 1 by current failure zone bit E_I_;

At E_I is 1 o'clock, and the fault processing module of HCU inside then enters second level exception handles, and in this exception handles, HCU lights trouble light MIL, and the demand torque to the ISG motor carries out following processing simultaneously:

Charging moment of torsion＜=DCDC the input current of demand multiply by electrokinetic cell voltage

The booster torquemoment of demand=0.

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