KR101327033B1 - Method of the Motor Torque Control for Preventing Reverse-traveling on Slope Road for a Fuel cell and a Electric Vehicle by Real Time Slope Prediction Algorithm - Google Patents

Abstract

The present invention relates to an algorithm for determining whether the vehicle is pushed by comparing the current vehicle speed and acceleration with a reference value when the pedal value is recognized by the pedal value, and predicting the slope angle and calculating the back creep torque. Knowing the driving torque of the vehicle and the acceleration of the vehicle, it is possible to predict the real-time inclination of the climbing road, and by calculating the appropriate creep torque command value, it is possible to solve the initial climbing phenomenon in the excessive slope without the supplementary means such as the ramp rolling prevention device.

Description

Method of the Motor Torque Control for Preventing Reverse-traveling on Slope Road for a Fuel cell and a Electric Vehicle by Real Time Slope Prediction Algorithm}

The present invention is a technique to apply the real-time gradient prediction algorithm as a method for controlling the emergency motor torque to prevent the skid during climbing of fuel cells and electric vehicles.

In a typical internal combustion engine vehicle, since the idle torque of the engine is transmitted to the torque converter and the transmission even when the accelerator pedal and the brake pedal are not stepped while driving, the creep driving is performed while the vehicle is gradually maintained at a small speed. When the vehicle is on the road driving situation, not only the rolling resistance but also the slope resistance are received. When the vehicle is stopped on the road due to the friction braking force by the driver's brake pedal operation, the vehicle releases the brake pedal. Pushed behind this. In order to get out of the back of the vehicle, the driver may press the brake pedal again or operate the accelerator pedal to prevent the vehicle from rolling. In order to eliminate the inconvenience of the operation to prevent the back from driving on the climbing road, even if the accelerator pedal and the brake pedal are not applied, a certain amount of friction brake is maintained to prevent the skid, and the driver applies the accelerator pedal again. A creep control technology is introduced that releases the friction brake and returns to normal operation.

Fuel cell and electric vehicles require creep control algorithm to generate torque similar to engine idle torque to satisfy the same driving feeling as general internal combustion engine cars, and on creep road with creep control algorithm to improve driving comfort when creep driving. The technology to prevent the rolling when restarting after the stop is necessary.

The following prior art document relates to an anti-rolling control device and method for a hybrid electric vehicle, and related technologies are disclosed in claims 3 and 3.

KR 10-2007-0065031 A

The present invention detects the signal and the vehicle speed of the brake pedal in the driving state in order to prevent the fall according to the road surface when the slope of the fuel cell or electric vehicle stops, and if it is determined to prevent the skid to extract the acceleration and road slope of the vehicle to prevent the fall In order to control the motor torque in order to control the motor torque, it is possible to prevent the initial rolling of the back which can be applied when the Hill-start Assist Control (HAC) or the acceleration sensor (G sensor) is fixed. It is an object of the present invention to provide an emergency creep torque control method that can be applied to low-cost fuel cells and electric vehicles.

According to the present invention for achieving the above object, when the pedal value is recognized as the emergency climbing plate creep area, the present vehicle speed and acceleration are compared with the reference value to determine whether the vehicle is pushed, predicting the climbing slope angle, and calculating the climbing creep torque. Algorithm that can know the driving torque of the motor and the acceleration of the vehicle can predict the real-time inclination of the climbing road, and calculates the appropriate creep torque command value to compensate for the initial climbing phenomenon even on the excessive slopes It can be solved without any means.

The present invention can predict the real-time slope of the climbing road by knowing the driving torque of the motor and the acceleration of the vehicle, and by improving the proper creep torque command value, it is possible to improve the initial climbing phenomenon even in the excessive slope without the auxiliary means such as the slope prevention device. In addition, by real-time feedback control of the relationship between the slope of the current torque and the acceleration in an iteration loop, the prediction accuracy of the slope can be increased without using an acceleration sensor.

1 is a block diagram and a slope inclination angle and a climbing creep torque calculation formula that can solve the initial climbing phenomenon in the slope without the slope prevention device, Figure 2 is an emergency climbing prevention torque control logic, Figure 3 is the creep torque and the vehicle speed Is a map of.

DETAILED DESCRIPTION Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, and as an example, those skilled in the art to which the present invention pertains may be embodied in various different forms. It is not limited to the embodiments described, and described in detail with respect to the preferred embodiment of the present invention with reference to the accompanying drawings as follows.

As shown in Fig. 1, the vehicle acceleration required for vehicle backing is branched in the direction parallel to the ground (x: transverse direction) and the direction perpendicular to the ground with respect to the direction of gravity, of which the rolling friction force perpendicular to the ground is the lateral force. It is very small compared to and can be ignored. Therefore, when the moment equation for the ground is derived, the back slope angle and the back creep torque are calculated and output to the motor as shown in FIG. 1 for the inclination angle prediction value, the motor torque, the tolerance weight, the acceleration, the gear ratio, the tire companion diameter, and the gravity acceleration.

This will be described in detail in FIG. 2. When the normal torque control is started, the failure signal of the slope road vehicle preventing device or the acceleration sensor is checked (step S01). If it is not a fault, go to step S02 to continue normal torque control, and if it is a fault, go to the pedal value judgment of S03. In step S03, the accelerator pedal value <the preset accelerator pedal value (D_A) And the brake pedal value <_BIs satisfied, it starts the emergency climbing creep control in step S04 because it is a creep control region that does not generate axel torque or brake (regen) torque. At this time, if the condition of step S03 is not satisfied, the process returns to step S02 and normal torque control is continued. When emergency creep control in step S04 starts, the initial value of creep torque (CrpTq) in step S05.₀) Is set to the creep basic torque value, and the initial value of the inclination angle prediction value (θ)₀) Is initially set to 0. Subsequently, the pedal value judgment is repeated as in step S06 to step S03, and the accelerator pedal value <the preset accelerator pedal value (D_A) And the brake pedal value <_B) If it is not satisfied, it is out of the creep control area.In step S07, iteration index n = 1 and the process returns to step S02 to continue normal torque control._A) And the brake pedal value <_BIf satisfied, proceed to step S08. In step S08 the current vehicle speed (Spd_n) Is the preset creep median speed (V_CrpMid), The preset creep median speed (V)_CrpMidDenotes a boundary condition that distinguishes the operation region A and the operation region B in FIG.

The relationship map between the creep torque value and the vehicle speed in step S08 is divided into a driving area A and a driving area B, and the driving area A is a creep base torque value (Creep_Torque_Base) <creep torque value <creep_Torque_Max), The vehicle speed is an area where the vehicle speed <creep middle speed value (V _CrpMid ), and the vehicle speed decreases linearly in the negative direction starting from the point where the vehicle speed is 0 and the creep torque value is the creep_Torque_Base. Value increases the line 1-1 (line1-1) diagram and after a certain point, the creep torque value remains constant, and the vehicle speed only increases to the creep intermediate speed value (V _CrpMid ). A line 2-1 (line2-1) diagram in which the vehicle speed decreases and the creep torque value increases, starting at any point between zero and the creep mid-velocity value (V _CrpMid ). While creep torque value is constant, Line to increase the vehicle speed, only the middle creep speed value _{(V CrpMid) 2-2 (line 2-2} ) is a diagram that contains the region, and the operation region B, the linearly as the vehicle speed is increased from the operating range A The line with decreasing creep torque value is a line 2-3 (line2-3) which extends from the line 1-2 and the maximum vehicle speed does not exceed the creep limit vehicle speed VcrpLim, as the vehicle speed increases. The maximum vehicle speed includes a line 2-3 (line2-3) diagram that does not exceed the creep limit vehicle speed VcrpLim while extending linearly in the line 2-2 as the creep torque decreases. The lines 1-3 and the line 2-3 are areas in which the creep torque value at the creep limit vehicle speed VcrpLim is zero.

If the current vehicle speed Spd _n <the predetermined creep intermediate speed value (V _CrpMid ) in step S08, the flow proceeds to step S10 to perform iteration control of the operation area A, and the current vehicle speed Spd _n > the set creep middle speed. If the speed value V _CrpMid , the flow proceeds to step S09 to determine the creep torque according to the creep torque reduction maps of the lines 1-3 and the line 2-3 in the operation region B and return to the previous step S06. In operation S10, the current acceleration Acc _n is compared with the preset minimum acceleration value A _SlopeMin . The minimum acceleration value A _SlopeMin is a minimum set value which is determined by the vehicle _driving and is a negative value.

Current acceleration (Acc_n) <Minimum acceleration value (A_Slopemin), The vehicle is in the rolling state, and after estimating the slope inclination in step S11, the slope creep torque corresponding to the inclination angle prediction value is calculated in step S12, and the creep torque (CrpTq) in step S13._n) Creep Base Torque (CrpTq)₀) To creep maximum torque (CrpTq)_mxSet the boundary so that it enters between If, in step S10 the current acceleration (Acc_n) <Minimum acceleration value (A_SlopeminIf it is not), the vehicle is not a vehicle jungle, so the process proceeds to step S14 to maintain the creep torque and the inclination angle prediction value as previous values, and then proceeds to step S13.

Back slope

) Back creep torque

)

Θ: estimated angle of inclination, Tq: motor torque, M _veh : tolerance weight, Acc: acceleration, GR: gear ratio, R _tire : diameter of tire, g: acceleration of gravity

Here, the process proceeding to S10 ~ S13 corresponds to the line 1-1 (line 1-1) at the time of stop climbing in FIG. The process of S10-S14 corresponds to line 1-2 when stopping climbing and line 2-2 when not stopping. After S13, the iteration index n is obtained. It increments by 1 and returns to before S06 to repeat the algorithm.

S11: Back slope inclination prediction
S12: Back Creep Calculation

Claims (8)

delete delete In the emergency back rolling prevention motor torque control method of fuel cell and electric vehicle,
Step S01 to determine the failure of the slope vehicle prevention device or the acceleration sensor,
In step S01, when the failure is determined, step S02 determines whether the accelerator pedal value and the brake pedal value are smaller than the preset accelerator pedal value and the brake pedal value;
In step S02, when the accelerator pedal value and the brake pedal value are not smaller than the predetermined accelerator pedal value and the brake pedal value, step S03 for performing normal torque control;
In step S02, when the accelerator pedal value and the brake pedal value are smaller than the predetermined accelerator pedal value and the brake pedal value, step S04 to start emergency lamp creep control;
The emergency ramp creep control of step S04 sets the initial creep torque initial value (CrpTq ₀ ) to the creep basic torque value, and initially sets the initial angle value of the inclination angle (θ ₀ ) to 0;
After step S05, determining whether the accelerator pedal value and the brake pedal value are smaller than the preset accelerator pedal value and the brake pedal value;
In the step S06, if the accelerator pedal value and the brake pedal value are not smaller than the preset accelerator pedal value and the brake pedal value, step S07 of performing normal torque control out of the creep control area,
When the accelerator pedal and brake pedal values are smaller than the preset accelerator pedal and brake pedal values in step S06, step S08 includes comparing the current vehicle speed with a preset creep intermediate speed value (V _CrpMid ), and the preset creep. The intermediate speed value (V _CrpMid ) is a boundary point for distinguishing each driving area in the relationship map between the driving area creep torque value and the vehicle speed. 4. The relationship map between the creep torque value and the vehicle speed in step S08 is divided into a driving area A and a driving area B, wherein the driving area A is a creep base torque value (Creep_Torque_Base) <creep torque value <creep maximum torque Value (Creep_Torque_Max) and the vehicle speed <creep intermediate speed value (V _CrpMid ), the vehicle speed is linearly negative in the starting point at the point where the vehicle speed is 0 and the creep torque value is the creep torque value (Creep_Torque_Base). And the creep torque value increases to line 1-1 (line1-1) and the creep torque value is constant after a certain point, and the vehicle speed increases to the creep intermediate speed value V _CrpMid . line 1-2) Line 2-1 (line 2-1) where the vehicle speed decreases and the creep torque value increases, with the vehicle speed starting at any point between zero and the creep intermediate speed value (V _CrpMid ). The creep torque after a certain point Constantly, only the vehicle speed is an area including a line 2-2 diagram that increases to a creep intermediate speed value V _CrpMid , and the driving area B is increased as the vehicle speed increases from the driving area A. A line in which the creep torque decreases linearly and extends in the line 1-2, where the maximum vehicle speed does not exceed the creep limit vehicle speed VcrpLim. As the vehicle speed increases, the creep torque decreases linearly and extends from the line 2-2, where the maximum vehicle speed does not exceed the creep limit vehicle speed VcrpLim. And the lines 1-3 and lines 2-3 are areas in which the creep torque value at the creep limit vehicle speed VcrpLim is zero. Control method. 5. The method of claim 4, wherein when the vehicle speed Spd _n is smaller than a predetermined creep intermediate speed value V _CrpMid in step S08, the _{magnitude of the} current acceleration Acc _n and the minimum acceleration value A _SlopeMin are compared. If the current vehicle speed Spd _n is greater than the predetermined creep intermediate speed value V _CrpMid in step S08, the control unit B proceeds to step S09. And determining creep torque according to the creep torque reduction maps of the lines 1-3 and the line 2-3 and returning to step S06 before returning to step S06. According to claim 5, If the current acceleration Acc _n is less than the minimum acceleration value (A _SlopeMin ) in the step S10 The slope inclination angle in step S11

And the creep torque corresponding to the estimated slope angle in step S12 (

, Θ: predicted inclination angle, Tq: motor torque, M _veh : tolerance weight, Acc: acceleration, GR: gear ratio, R _tire : tire diameter, g: gravity acceleration, n: iteration index) Creep basic torque value (CrpTq ₀ ) <creep torque (CrpTq _{n =}

) <A crimping prevention motor torque control method for emergency climbing of a fuel cell and an electric vehicle, wherein the boundary is set to be a creep maximum torque value (CrpTq _mx ). The method according to claim 6,
If the current acceleration Acc _{n n} is greater than the minimum acceleration value (A _SlopeMin ) in step S10, it is determined that the vehicle is not the vehicle and proceeds to step S14 to maintain the creep torque and the inclination angle prediction value to the previous value and Emergency back skid prevention motor torque control method of electric vehicle. The method of claim 7, wherein
The process proceeding to the step S10 to S13 corresponds to the line 1-1 (line 1-1) when the stop climbing on the relationship map between the creep torque value and the vehicle speed, and the line 2-1 (line 2 when non-stop climbing) -1), the process proceeds to steps S10 to S13 corresponds to the line 1-2 when the stop climbing, and the line 2-2 when non-stop climbing Emergency back rolling prevention motor torque control method of a fuel cell and an electric vehicle, characterized in that corresponding to.

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