JP4547762B2 - Electric vehicle motor control device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a motor control device for an electric vehicle that controls a drive motor in the electric vehicle.
[0002]
[Prior art]
Generally, in an electric vehicle such as a golf cart, the maximum speed is limited to about 20 km / h, and when the maximum speed is exceeded, a process for cutting the motor torque is required. In some cases, the driving of the motor becomes unnatural and gives a sense of incongruity to driving.
[0003]
Also, the general torque characteristics of the motor are as shown in FIG. 4. When the output torque is 100% when the accelerator is 100% open, excessive torque is generated in the low speed range and the drive fee is increased. The ring gets worse. Therefore, as shown by the dotted line in the figure, when the limiter control is performed to keep the motor torque below a certain level in the low speed range, the drive feeling is improved, but the motor performance cannot be fully exhibited. Acceleration will be worse.
[0004]
Conventionally, in order to enable smooth acceleration, the target speed at that time is determined from the detection results of the accelerator opening and the current speed of the vehicle, and the current speed is determined as the determined target speed. A motor control device for an electric vehicle has been developed which obtains a command speed in consideration of a speed change rate necessary for convergence to a predetermined calculation process and controls the number of revolutions of the motor according to the command speed. (See JP 62211805).
[0005]
[Problems to be solved by the invention]
The problem to be solved is that in the conventional motor control device for an electric vehicle in which the command speed is obtained from the target speed determined in accordance with the accelerator opening and the rotation speed of the motor is controlled, the accelerator pedal is suddenly changed. When stepped on, the target speed changes suddenly and the deviation between the command speed and the current speed becomes large. To achieve smooth acceleration, it is necessary to set the control gain considerably low and converge to the target speed. However, controllability is deteriorated due to the time required.
[0006]
Further, in such a conventional motor control device for an electric vehicle, it is impossible to perform control for smoothly decelerating while limiting the traveling speed on a downhill.
[0007]
[Means for Solving the Problems]
The present invention detects an accelerator opening degree and a current speed of a vehicle, determines a target speed from the detected accelerator opening degree, and calculates a predetermined speed according to the determined target speed and the current speed. This is a motor control device for an electric vehicle that controls the motor so that the command speed is obtained by processing, and limits the traveling speed even when the accelerator pedal is depressed suddenly or downhill. In order to optimally control acceleration / deceleration to converge the current speed to the target speed, the detected values of the accelerator opening and the current speed, the target speed, and the preset maximum acceleration / deceleration of the vehicle limit value command pressure by a predetermined arithmetic processing using, and means asking you to deceleration, the the obtained command pressure, means for updating the command speed with deceleration, current and the updated command speed velocity Deviation from It means for calculating a torque close to zero, and means for controlling the torque of the motor in accordance with the calculation result, obtaining the first acceleration using the limit value of the maximum acceleration of the accelerator opening and the vehicle, the target The second acceleration based on the deviation between the speed and the current speed is obtained. When the first acceleration is smaller than the second acceleration, the first acceleration is set as the command acceleration, and the first acceleration is equal to or higher than the second acceleration. In some cases, the second acceleration is set as the commanded acceleration .
[0008]
【Example】
FIG. 1 shows a configuration example of a motor control device for an electric vehicle for carrying out the present invention.
[0009]
The motor control device for the electric vehicle reads the detected values of the accelerator opening detector 1 for detecting the accelerator opening, the speed detector 2 for detecting the current speed of the vehicle, and the accelerator opening and the current speed. The arithmetic processing unit 3 for obtaining a predetermined target speed from a preset table and performing a predetermined arithmetic process to obtain a motor drive control amount for converging the current speed to the target speed; The motor control unit 4 performs drive control of the motor 6 via the inverter 5 in accordance with the control amount. The rotation number N of the motor 6 is detected by the rotation detector 7, and the rotation number N is fed back to the motor control unit 4.
[0010]
The arithmetic processing unit 3 and the motor control unit 4 are specifically configured by an ECU. As the motor 6, for example, a three-phase magnet synchronous generator capable of torque control is used.
[0011]
The present invention is configured as described above, and basically, in the arithmetic processing unit 3, a command speed in consideration of a speed change rate necessary for converging the current speed to the target speed is subjected to predetermined arithmetic processing. I want to ask.
[0012]
The command speed Vs in consideration of the speed change rate ΔV necessary for converging the current speed V to the target speed Vo is obtained by an arithmetic process based on the following equations (1) and (2).
[0013]
Vs = Vo−ΔV (1)
[0014]
ΔV = K / (Vo−V) (2)
K: Constant [0015]
In particular, the present invention provides command acceleration / deceleration by a predetermined calculation process using each detected value of the accelerator opening and the current speed, a target speed, and a preset maximum acceleration / deceleration limit value of the vehicle. A means for updating the command speed using the obtained command acceleration / deceleration, a means for calculating a torque that brings the deviation between the updated command speed and the current speed close to zero, The drive control of the motor 6 is performed using the calculated torque as a control amount.
[0016]
Each of these means is executed in the arithmetic processing unit 3.
[0017]
FIG. 2 shows a specific processing flow in the arithmetic processing unit 3. A specific process according to the flow will be described below.
[0018]
First, the accelerator opening degree H (%) and the current speed V are detected every fixed period ΔT (step S1), and a predetermined target speed Vo is determined from a table set in advance according to the detected accelerator opening degree H. Is obtained (step S2).
[0019]
Next, it is determined whether or not the obtained target speed Vo is larger than the current speed V (step S3). At that time, if Vo> V, the process enters the acceleration mode, and if Vo ≦ V. Enters deceleration mode processing.
[0020]
In the processing in the acceleration mode, it is determined whether or not the command speed Vs obtained as described above is smaller than the current speed V (step S4). The command speed Vs is rewritten and reset so as to be the same value as the current speed V (step S5).
[0021]
At that time, if Vs ≧ V, it is determined whether or not the command speed Vs is larger than the target speed Vo (step S6). If Vs> Vo, the command speed Vs at that time is the target speed Vs. It is rewritten and reset to have the same value as Vo (step S7). At that time, if Vs ≦ Vo, the command speed Vs is not reset at all.
[0022]
Next, acceleration 1 is obtained by multiplying a predetermined maximum acceleration limit value by the accelerator opening H (step S8), and the acceleration is obtained by multiplying the deviation between the target speed Vo and the current speed V by a predetermined acceleration gain. 2 is obtained (step S9), and it is determined whether or not the acceleration 1 is smaller than the acceleration 2 (step S10).
[0023]
At that time, if acceleration 1 <acceleration 2, the command acceleration α is set to be acceleration 1 (step S11). If acceleration 1 ≧ acceleration 2, the command acceleration α is set to be acceleration 2 (step S12).
[0024]
Then, the command speed Vs is updated by adding a speed component obtained by multiplying the set command acceleration α by a certain period (cycle) ΔT to the command speed Vs at that time (step S13).
[0025]
FIG. 3 shows the torque characteristics with respect to the speed deviation between the current speed V and the target speed Vo with the accelerator opening H as a parameter. The acceleration 2 represents the rising characteristic from the speed deviation of 0, and the acceleration 1 is the value after the rising. The characteristics of
[0026]
Next, it is determined whether or not the updated command speed Vs is greater than the current speed V plus a preset speed deviation limit value (step S14).
[0027]
At this time, if the command speed Vs is larger, a speed deviation Err between the command speed Vs and the current speed V is obtained (step S15). If the command speed Vs is smaller, the command speed Vs plus the speed deviation limit value is used as a new command speed Vs (step S16), and the new command speed Vs and the current speed V A speed deviation Err is obtained (step S15).
[0028]
Finally, the torque that brings the speed deviation Err close to zero is calculated as proportional control (Err + P gain) + integral control (ΣErr + I gain) (step S17).
[0029]
In the acceleration mode processing, it is determined whether or not the command speed Vs obtained as described above is larger than the current speed V (step S18). The command speed Vs at that time is rewritten and reset so as to be the same value as the current speed V (step S19).
[0030]
At that time, if Vs ≦ V, it is determined whether or not the command speed Vs is smaller than the target speed Vo (step S20). If Vs <Vo, the command speed Vs at that time is the target speed Vs. It is rewritten and reset to have the same value as Vo (step S21). At that time, if Vs ≧ Vo, the command speed Vs is not reset at all.
[0031]
Next, a deceleration is obtained by multiplying a deviation between the current speed V and the target speed Vo by a predetermined deceleration gain (step S22), and whether or not the deceleration is larger than a preset maximum deceleration. A determination is made (step S23).
[0032]
At that time, if deceleration> maximum deceleration, the command deceleration β is set to the maximum deceleration (step S24). If deceleration ≦ maximum deceleration, the command deceleration β is set so as to be the deceleration at that time (step S25).
[0033]
Then, the command speed Vs is updated by adding a speed component obtained by multiplying the set command deceleration β by a certain period (cycle) ΔT to the command speed Vs at that time (step S26).
[0034]
Next, it is determined whether or not the updated command speed Vs is smaller than the current speed V plus a preset speed deviation limit value (step S27).
[0035]
At this time, if the command speed Vs is smaller, a speed inference Err between the command speed Vs and the current speed V is obtained (step S15). If the command speed Vs is larger, the command speed Vs plus the speed deviation limit value is used as a new command speed Vs (step S28), and the new command speed Vs and the current speed V are calculated. A speed deviation Err is obtained (step S15).
[0036]
Finally, the torque that brings the speed deviation Err close to zero is calculated as proportional control component (Err + P gain) + integral control component (ΣErr + I gain) (step S16).
[0037]
As described above, according to the present invention, for the target speed Vo determined by the accelerator opening H, the command speed Vs approximated to the current speed Vo is generated according to a predetermined rule, and the accelerator opening H and the current speed V are generated. The command speed Vs is updated by using the command acceleration / deceleration α, β obtained by a predetermined calculation process using the target speed Vo and the preset maximum acceleration / deceleration limit values. By applying so-called follow-up control in which the control amount is a torque that brings the deviation between the command speed Vs and the current speed V close to zero, the drive control of the motor 6 can be performed with a high gain. , It becomes possible to control the deceleration with high accuracy.
[0038]
Therefore, torque adjustment is automatically performed in response to changes in vehicle weight, sudden depression of the accelerator pedal, changes in driving conditions (such as driving on uphill, downhill or flat roads, driving resistance due to wind, etc.). Because it is done, drive feeling is improved. In particular, since negative torque by regenerative braking is applied to the motor 6 on the downhill, smooth deceleration control can be performed while limiting the speed.
[0039]
【The invention's effect】
As described above, in the motor control device for an electric vehicle according to the present invention, the accelerator opening and the current speed of the vehicle are detected, the target speed is determined from the detected accelerator opening, and the determined target speed and When a command speed corresponding to the current speed is obtained by a predetermined calculation process and the motor is controlled so as to obtain the command speed, each detected value of the accelerator opening and the current speed, a target speed, and a preset speed are set in advance. The command acceleration / deceleration is obtained by a predetermined calculation process using the maximum acceleration / deceleration limit value of the vehicle, and the command speed is updated using the obtained command acceleration / deceleration. calculates a torque close to zero a deviation between the command speed and the current speed, after to perform the torque control of the motor in accordance with the calculation result, in particular, a limit value of the maximum acceleration of the accelerator opening and the vehicle The first acceleration is obtained, the second acceleration based on the deviation between the target speed and the current speed is obtained, and when the first acceleration is smaller than the second acceleration, the first acceleration is set as the command acceleration, When the acceleration of 1 is equal to or higher than the second acceleration, the second acceleration is set as the command acceleration . Therefore, the speed, acceleration and deceleration can be controlled with high gain with high accuracy. Have.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration example of a motor control device for an electric vehicle for carrying out the present invention.
FIG. 2 is a diagram showing a specific processing flow in an arithmetic processing unit of the same configuration example.
FIG. 3 is a diagram showing a torque characteristic with respect to a speed deviation between a current speed and a target speed using an accelerator opening as a parameter.
FIG. 4 is a diagram showing a general torque characteristic of a motor in the same configuration example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Accelerator opening detector 2 Speed detector 3 Arithmetic processing part 4 Motor control part 5 Inverter 6 Motor 7 Rotation detector

Claims (1)

The accelerator opening and the current speed of the vehicle are detected, a target speed is determined from the detected accelerator opening, and a command speed corresponding to the determined target speed and the current speed is obtained by a predetermined calculation process. In the motor control device for an electric vehicle that controls the motor so as to achieve the command speed, the detected value of the accelerator opening and the current speed, the target speed, and the preset maximum acceleration / deceleration limit value of the vehicle Means for obtaining command acceleration / deceleration by predetermined arithmetic processing using, means for updating command speed using the obtained command acceleration / deceleration, and deviation between the updated command speed and current speed It means for calculating a torque close to zero, and means for performing a motor torque control in accordance with the calculation results, determined the first acceleration using the limit value of the maximum acceleration of the accelerator opening and the vehicle In addition, the second acceleration based on the deviation between the target speed and the current speed is obtained, and when the first acceleration is smaller than the second acceleration, the first acceleration is set as the command acceleration, and the first acceleration is the second acceleration. A motor control device for an electric vehicle characterized in that the second acceleration is set as a command acceleration when the acceleration is equal to or greater than the acceleration .

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