JP2745304B2 - Acceleration / deceleration control method and device for electric vehicle - Google Patents

Description

The present invention relates to an electric vehicle acceleration control method and apparatus,
In particular, it relates to improvement of the rising characteristics. [Related Art] An electric vehicle controls acceleration and deceleration of a motor by controlling a rotation speed of a motor by a driver's operation of an accelerator. Further, a control device is provided for controlling the rise of an actual motor drive command in response to an accelerator command in order to smooth running during acceleration / deceleration. As such a control device, for example, there is a control device in which a rise time of an accelerator command current is set to a constant value, and a time until the rotation speed of the motor becomes a value corresponding to a command from the accelerator is set. According to such a method, it is possible to prevent a sudden change in the motor speed. That is, if the rise time is set to be long, the rise of the motor current becomes gentle, and smooth acceleration / deceleration, in particular, starting is possible. Japanese Patent Application Laid-Open No. S51-131014 discloses a control device in which a time constant circuit element can be freely inserted by a changeover switch and a rise time of an accelerator command current can be freely changed. [Problems to be Solved by the Invention] In such a conventional control device, if the rise time of the accelerator command current is set to be long, acceleration / deceleration, particularly start-up becomes smooth, but the acceleration is not sufficient, and There is a problem that the feeling of acceleration and deceleration felt by the person is poor. Also, if the rise time is shortened, there is a problem that mechanical backlash and vehicle torsional vibration occur. SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it is possible to prevent a shock at the time of acceleration / deceleration and to provide a method and apparatus for controlling acceleration / deceleration of an electric vehicle which can ensure a sufficient feeling of acceleration for a driver. The purpose is to provide. [Means for Solving the Problems] An acceleration / deceleration control method for an electric vehicle according to the present invention detects a driver's instruction on acceleration / deceleration of the electric vehicle and the number of revolutions of a motor driving the electric vehicle. A motor output torque command value, which is a target value of the output torque of the motor, is calculated and calculated based on the detection result, and the output torque of the motor approaches the motor output torque command value.
An acceleration / deceleration control method for an electric vehicle in which an actual torque command value for an inverter controller that controls power supply to the motor is gradually changed. The greater the difference between the motor output torque command values, the smaller the amount of change in the actual torque command value. After the end of the period in which mechanical play occurs in the mechanical system, the greater the difference between the actual torque command value and the motor output torque command value, the greater the actual torque. The amount of change in the command value is increased to bring the actual torque command value closer to the motor output torque command value. Further, the acceleration and deceleration control device for the electric vehicle according to the present invention,
A motor output torque command value that is a target value of the output torque of the motor from a drive motor that drives the electric vehicle, a signal about a driver's instruction about acceleration and deceleration of the electric vehicle, and a signal about the number of rotations of the motor. Controller, which calculates the actual torque command value based on the motor output torque command value from the EV controller, and a start-up characteristic calculation unit which calculates the actual torque command value based on the motor output torque command value from the EV controller. And an inverter controller for controlling power supply to the motor, wherein the rising characteristic calculating section includes a current actual torque command value and a motor output torque command value during a period in which the mechanical system at the initial stage of acceleration / deceleration has play. The larger the difference between the two, the smaller the amount of change in the actual torque command value, It is characterized in that the larger the difference between the torque command value and the motor output torque command value is, the larger the amount of change in the actual torque command value is, and the closer the actual torque command value is to the motor output torque command value. [Operation] The motor output torque command value is calculated from the driver's accelerator pedal depression amount and the like. Then, the command value to the inverter controller is changed so that the output of the motor becomes this value. At this time, the actual torque command value calculated by the rise calculation unit is changed to reduce a shock caused by excessive acceleration. To control the motor. When a change in acceleration / deceleration is instructed, the change in the actual torque command value increases as the difference between the current actual torque command value and the motor output torque command value increases during the period of play in the mechanical system at the beginning of acceleration / deceleration. Is reduced, and after the end of the period in which play occurs in the mechanical system, the larger the difference between the actual torque command value and the motor output torque command value is, the larger the amount of change in the actual torque command value is. Therefore, the change in the actual torque command value can be made very smooth, and the occurrence of shock due to mechanical play can be effectively prevented. For this reason, a shock such as a mechanical backlash in the initial stage of acceleration / deceleration can be suppressed, and a sufficient feeling of acceleration can be obtained. [Embodiment] An acceleration / deceleration control method and apparatus for an electric vehicle according to the present invention will be described with reference to the drawings. A vehicle 100, which is an electric vehicle, travels by transmitting rotation of a motor 10 to a diamond 14 via a transmission 12. A signal A about the speed of the vehicle 100 by the accelerator 16 which is one of the acceleration / deceleration means is input to the EV controller 18. Then, a signal ω about the number of rotations of the motor 10 obtained by the rotation sensor 19 is also input to the EV controller 18. Here, the acceleration / deceleration means includes not only the accelerator 16 but also a brake.
Is performed, for example, by detecting the amount of depression of an accelerator. The EV controller 18 calculates and calculates a motor output torque command T0 from a vehicle characteristic map stored in advance in accordance with the values of the input signals A and ω. Then, the motor output torque command T0 is input to the torque rise characteristic calculation unit 20. The rising characteristic calculation unit 20 supplies the actual torque command value T to the inverter controller 22 based on the input motor output torque command T0. Then, the inverter controller 22 controls the switching of the inverter main circuit 24 based on the actual torque command value T, and performs PWM (pulse width modulation) control of the rotation of the motor 10 by the power of the battery 26. In this way, the rotation of the motor 10 is controlled according to the command A for the speed by the accelerator 16. Note that the flowchart for the above operation is described in the second section.
Shown in the figure. Next, the content of the calculation in the rise characteristic calculation unit 20, which is a feature of the present invention, will be described. FIG. 3 shows that the value of the motor output torque command value T0 calculated by the EV controller 18 according to the signal A from the accelerator 16 is
The change of the actual torque command value T which is the output of the rise calculation unit 20 in the case of T0a is shown. As described above, the actual torque command value T rises gently at the beginning when the acceleration instruction from the accelerator 16 is received. For this reason, shock due to mechanical play can be prevented. The area I below the broken line in the figure corresponds to this. Then, the actual torque command value T sharply increases thereafter and quickly approaches the motor output torque command T0a. The area indicated by II in the figure corresponds to this, and here, a feeling of acceleration for the driver is ensured. The boundary between the regions I and II is determined based on whether the difference between the actual torque command value T and the motor output torque command value T0a is larger than a predetermined value, for example, B. In order to obtain such an actual torque command value T, the rise characteristic calculation unit 20 performs the following calculation. Tn + 1 = Tn + K1 / (T0a−Tn) In other words, in the region I, the larger the difference between the current actual torque command value Tn and the motor output torque command T0a, the smaller the increase amount of the actual torque command value. Therefore, the amount of increase of the actual torque command value T gradually increases. As a result, the torque increases very smoothly, and smooth start and acceleration can be performed. Next, in the area II, the actual torque command value T is calculated by the following calculation. Tn + 1 = Tn + K2 (T0a−Tn) As described above, the larger the difference between the current actual torque command value T and the motor output torque command T0a, the larger the increase amount of the actual torque command value T. Therefore, the difference between the actual torque command value T and the motor output torque command value T0a is sharply reduced, and the actual torque command value T smoothly matches the motor output torque command T0a. In the above description, as the value of the actual torque command value T, the current value is Tn, and the new actual torque command value is Tn + 1.
It was expressed as K1 and K2 are constants set by the vehicle, and the value of K2 is smaller than 1. The ranges of the regions I and II are set according to the amount of backlash of the vehicle. That is, depending on the characteristics of the vehicle, if the play is large, the range of the region I is set large. The set time t0 until the actual torque command value T reaches the motor output command value T0a needs to be a time during which the driver feels a sense of acceleration. It is generally said that the time during which the driver feels a sense of acceleration is one second. Therefore, the set time
The above constants K1 and K2 are set so that t0 is within 1 second. FIG. 4 is a flowchart showing the operation of the rise characteristic control calculation unit 20. [Effects of the Invention] As described above, according to the acceleration control method for an electric vehicle of the present invention, a shock during acceleration / deceleration can be obtained even though a good acceleration / deceleration feeling can be obtained according to the amount of depression of the accelerator or brake. It can be effectively prevented.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a system configuration to which an embodiment of an acceleration / deceleration control method for an electric vehicle according to the present invention is applied, and FIG. 2 shows an overall configuration of control in the embodiment. FIG. 3 is a flowchart showing the change over time of the actual torque command value T in the embodiment, and FIG. 4 is a flowchart showing the operation of the rise characteristic calculating section 20 in the embodiment. 10 Motor 16 Accelerator (acceleration / deceleration means) 18 EV controller 20 Rise characteristic calculator 22 Inverter controller 24 Inverter main circuit

Claims (1)

(57) [Claims] In an electric vehicle in which DC power from a battery is controlled by an inverter main circuit to be converted into AC power and the AC power is used to drive a motor and transmit the output of the motor to a tire via a mechanical system, the acceleration and deceleration of the electric vehicle A motor output torque command value, which is a target value of the output torque of the motor, is calculated and calculated based on the instruction of the driver and the number of rotations of the motor driving the electric vehicle. In order to bring the output torque closer to the motor output torque command value, in an acceleration / deceleration control method for an electric vehicle in which an actual torque command value for an inverter controller that controls power supply to the motor is gradually changed, The larger the difference between the current actual torque command value and the motor output torque command value during the period in which backlash occurs, The amount of change in the torque command value is reduced, and after the end of the period in which mechanical play occurs in the mechanical system, the larger the difference between the actual torque command value and the motor output torque command value, the greater the change in the actual torque command value. An acceleration / deceleration control method for an electric vehicle, comprising: bringing a command value closer to a motor output torque command value. 2. An electric vehicle that controls DC current from a battery by an inverter main circuit to convert AC power, drives the motor with the AC power, and transmits the output of the motor to tires through a mechanical system. An EV controller that calculates a motor output torque command value, which is a target value of the motor output torque, from a motor, a signal about a driver's instruction on acceleration and deceleration of the electric vehicle, and a signal about the number of rotations of the motor. A rise characteristic calculation unit for calculating and calculating an actual torque command value based on the motor output torque command value from the EV controller; and a control unit for controlling the motor output torque so as to approach the motor output torque to the motor output torque command value. An inverter controller for controlling power supply; and During the period of play in the mechanical system at the initial stage of speed, the larger the difference between the current actual torque command value and the motor output torque command value is, the smaller the amount of change in the actual torque command value is, and the end of the period in which the mechanical system plays back The acceleration / deceleration of an electric vehicle is characterized in that the larger the difference between the actual torque command value and the motor output torque command value is, the larger the change amount of the actual torque command value is, and the actual torque command value approaches the motor output torque command value. Control device.