JP2019126201A - Control device of electric vehicle - Google Patents

Abstract

To provide a control device of an electric vehicle which can improve acceleration performance without the necessity for enlarging a motor and a battery, and raising performance.SOLUTION: In a control device of an electric vehicle having a gear transmission mechanism in which a torque transmission state is switched between a drive state that drive wheels are driven by motor torque outputted by a motor, and a driven state that the motor is driven by torque transmitted from the drive wheel side, when the electric vehicle is accelerated, a drive force for the acceleration is increased by bringing the gear transmission mechanism into the drive state by eliminating the backlash of the gear transmission mechanism by increasing the motor torque to a positive side in a direction in which the drive wheels are driven after temporarily bringing the gear transmission mechanism into the driven state by increasing the motor torque to a negative side in which the drive wheels are braked (step S200; steps S201 to 210).SELECTED DRAWING: Figure 3

Description

  The present invention relates to a control device of an electric vehicle provided with at least a motor as a driving force source.

  Patent Document 1 describes an invention relating to a control device for a vehicle for the purpose of suppressing the occurrence of torsional vibration without reducing the responsiveness of power transmission. The invention described in Patent Document 1 is a control device of a vehicle having a power transmission member between a driving power source (motor) and a driving wheel, and is operated by a driver to change the traveling state of the vehicle. A signal output unit that outputs a traveling state change signal, and a torque control unit that controls the magnitude of an instruction torque to the motor according to an input of the traveling state change signal. When the traveling state change signal is input from the signal output unit, the torque control unit is set to the first command torque set to the first change rate, and to the second change rate having a smaller change rate than the first change rate. The second command torque and a third command torque set to a third change rate, which has a change rate larger than the second change rate, are sequentially output. Specifically, when the torque control unit receives a release signal of the brake operation from the signal output member, that is, when the driver's intention to start is detected, the torque control unit first receives the first torque gradient X (steep). Output the command torque. Then, a second command torque of torque gradient Y (slow gradient) is output (rate of change of torque gradient Y <rate of change of torque gradient X). Thereafter, the third command torque of torque gradient Z (smooth) is output (rate of change of torque gradient Z> rate of change of torque gradient Y). By the first command torque, rattling of parts forming the power transmission member is quickly reduced to suppress a decrease in acceleration responsiveness of the vehicle. Further, the generation of the torsional vibration in the rotary component forming the power transmission member is suppressed by the second command torque. Then, the vehicle is accelerated smoothly by the third command torque.

  Patent Document 2 describes an invention relating to a vehicle acceleration shock reducing device for the purpose of achieving both reduction of acceleration shock and improvement of responsiveness in rattling control. In the invention described in this patent document 2, the engine torque is a period from the time when the engine (driving power source) starts increasing the torque accompanying the acceleration to the time when a predetermined time elapses at the time of acceleration due to the increase of the accelerator opening. The command value is held at the limit torque smaller than the required torque command value. As a result, when performing the rattling control, the engine speed only slightly increases slightly, and the shock at the time of acceleration is reduced. Moreover, in the invention described in this patent document 2, by separately controlling the torque down time involved in the response in rattling control and the torque down amount involved in the reduction effect of the acceleration shock, the acceleration shock can be reduced. We are trying to achieve both mitigation and improvement in control responsiveness.

JP, 2014-233131, A JP, 2009-47080, A

  As described above, in the control device for a vehicle described in Patent Document 1, when the driver releases braking to accelerate the vehicle, a torque (first command torque) having a large change rate is first output from the motor Be done. As a result, rattling in a power transmission member such as a transmission or a differential mechanism is quickly reduced, and the acceleration response of the vehicle is improved accordingly. However, in order to further improve the acceleration performance, for example, it is necessary to mount a higher output motor and a higher performance battery.

  The present invention has been conceived focusing on the above technical problems, and does not involve upsizing or enhancing the performance of the motor or battery of the driving force source, that is, without changing the existing vehicle configuration. It is an object of the present invention to provide a control device of an electric vehicle capable of improving acceleration performance.

  In order to achieve the above object, the present invention provides a drive power source having at least a motor, a drive wheel, a gear transmission mechanism for transmitting torque between the drive power source and the drive wheel, and an output of the motor In the control device for an electric vehicle including a controller for controlling a motor torque, the gear transmission mechanism includes a drive state for driving the drive wheel by the motor torque and the motor by a torque transmitted from the drive wheel side. When the torque transmission state is switched between the driven state to be driven, a predetermined gear in the gear transmission mechanism is idled to cause a state in which torque is not transmitted, and the controller is configured to When accelerating the electric vehicle in response to the driver's request for acceleration, the motor torque is temporarily increased to the negative side of the direction in which the driving wheel is braked. After the gear transmission mechanism is brought into the driven state, the motor torque is increased on the positive side in the direction of driving the drive wheels to close the rattle and make the gear transmission mechanism into the driven state to accelerate the acceleration. Drive torque for increasing the gain of damping torque output from the motor in order to suppress the torsional vibration generated by increasing the motor torque to the positive side. is there.

  In the control device for the electric vehicle according to the present invention, when accelerating the electric vehicle using the motor as the driving power source, first, the motor torque is temporarily increased to the negative side, whereby the gear transmission mechanism is driven. To be When the gear transmission mechanism is in the driven state, the gear transmission mechanism is in a state in which the rattling caused by the backlash of the gear is the largest. Then, from this state, the motor torque is increased to the positive side, and the rattling is reduced at a stretch. The clogging of the rattle causes the gear transmission mechanism to be in a driving state, generating a driving force to accelerate the electric vehicle. As described above, when the gear transmission mechanism is switched from the driven state to the driven state, an impact force is generated due to collision of the tooth surfaces of the gears when the rattle is clogged. In the present invention, as described above, a state in which the rattle becomes maximum once is generated, and from this state, the gear transmission mechanism is driven to accelerate the electric vehicle while generating a collision due to rattling. Therefore, when accelerating the electric vehicle, backlash is performed in a state in which the collision energy at the time of backlash filling is maximized, and the collision energy is added to the rotational energy for generating the driving force. That is, as the collision energy is added, the driving torque for generating the driving force for acceleration is increased. After all, such an increase in drive torque does not contribute to the magnitude of the motor torque.

  Therefore, according to the present invention, the driving force that can be generated at the time of acceleration can be increased without increasing the size of the motor or battery for improving the output of the driving force source or enhancing the performance. That is, the acceleration performance of the electric vehicle can be improved without changing the existing vehicle configuration. Further, according to the present invention, when accelerating the electrically powered vehicle by the motor torque, the motor is controlled by the motor in order to suppress the torsional vibration generated in the drive system at the time of acceleration together with the control for operating the backlash of the gear transmission mechanism as described above. The gain (the degree of contribution) of the damping torque to be output is increased. For example, the gain of damping torque is increased according to the driver's acceleration demand so that the gain of damping torque also increases as the driver's acceleration demand increases. Therefore, when accelerating the electric vehicle, the acceleration performance of the electric vehicle can be improved without changing the existing vehicle configuration as described above, and the occurrence of shock and discomfort caused by torsional vibration at the time of acceleration It can be suppressed. As a result, the drivability of the electric vehicle to which the present invention is applied can be improved.

FIG. 1 is a diagram showing an example of a configuration (a drive system and a control system) of an electrically powered vehicle to which the present invention is applied. It is a flowchart for demonstrating an example (basic control flow) of control performed with the controller of the electric vehicle in this invention. It is a flowchart for demonstrating an example of the control performed by the controller of the electric vehicle in this invention, Comprising: It is a flowchart for demonstrating the detail of the control content of step S200 in the flowchart of FIG. It is a flowchart for demonstrating an example of control performed with the controller of the electric vehicle in this invention, Comprising: It is a flowchart for demonstrating the detail of the control content of step S300 in the flowchart of FIG. It is a flowchart for demonstrating an example of control performed by the controller of the electric vehicle in this invention, Comprising: It is a flowchart for demonstrating the detail of the control content of step S400 in the flowchart of FIG. It is a time chart for demonstrating the behavior of the vehicle at the time of performing control shown by each flow chart of Drawing 2, Drawing 3, Drawing 4, and Drawing 5. Drawing 5 is provided with the following. It is a figure for demonstrating the "drive state" in a gear transmission mechanism at the time of performing drive system rattle operation control in this invention, a "driven state", and "a rattling." It is a figure for demonstrating the effect at the time of performing control in this invention, Comprising: The change of the acceleration in the vehicle to which this invention is applied at the time of acceleration of a vehicle is shown, and the change of the acceleration in the conventional vehicle as a comparative example is shown. It is a time chart.

  Embodiments of the present invention will be described with reference to the drawings. The embodiment described below is merely an example of embodying the present invention, and does not limit the present invention.

  The vehicle to be controlled in the embodiment of the present invention is an electric vehicle having at least one motor as a driving force source. It may be an electric vehicle equipped with one or more motors as a driving force source. Alternatively, it may be a so-called hybrid vehicle equipped with an engine and a motor as a driving force source. For example, it may be a hybrid vehicle of a method of connecting an engine and a motor via a power split mechanism using a planetary gear mechanism. In any of the hybrid vehicles, any configuration may be employed as long as the driving force is generated by the motor torque output from the motor to allow the vehicle to travel (EV travel).

  FIG. 1 shows an example of a drive system (drive system and control system) of an electric vehicle to be controlled in the embodiment of the present invention. An electrically powered vehicle (hereinafter referred to as a vehicle) Ve shown in FIG. 1 includes a motor 2 as a driving power source 1. The vehicle Ve also includes a drive wheel 3, a gear transmission mechanism 4, a detection unit 5, and a controller (ECU) 6 as other main components. As described above, the driving power source 1 in the embodiment of the present invention may include the motor 2 and a plurality of other motors (not shown). In addition, the motor 2 and an engine (not shown) may be provided. Alternatively, it may be a hybrid drive unit provided with a motor 2 and an engine (not shown), and a transmission (not shown) such as a power split mechanism or a transmission.

  The motor 2 is, for example, a permanent magnet synchronous motor or an electric motor such as an induction motor, and is driven by the supply of electric power and functions as a motor that outputs a motor torque. In addition, it may be a so-called motor generator that has both the function as a prime mover and the function as a generator that generates electricity by being driven by receiving an external torque. The motor 2 has its output rotational speed and motor torque controlled electrically. Further, in the case of the motor generator, switching between the function as the prime mover and the function as the generator as described above is electrically controlled. Then, the motor 2 can output a motor torque in the direction of driving the drive wheels 3 described later and a motor torque in the direction of braking the drive wheels 3. In the embodiment of the present invention, as described above, the direction of the torque for driving the drive wheel 3 is positive, and the direction of the torque for braking the drive wheel 3 is negative.

  The driving wheel 3 is a wheel that generates the driving force of the vehicle Ve by transmitting the torque output from the driving force source 1, that is, transmitting the motor torque of the motor 2 in the example shown in FIG. is there. In the example shown in FIG. 1, the drive wheel 3 is connected to the motor 2 via a gear transmission mechanism 4 and a drive shaft 7 which will be described later. Therefore, in the example shown in FIG. 1, the vehicle Ve is configured as a rear wheel drive vehicle that transmits driving torque (motor torque) to the rear wheels (driving wheels 3) to generate driving force. The vehicle Ve in the embodiment of the present invention may be a front wheel drive vehicle that transmits driving torque to the front wheels to generate driving force. Alternatively, it may be a four-wheel drive vehicle that transmits driving torque to both the front and rear wheels to generate driving force.

  The gear transmission mechanism 4 is a power transmission mechanism that transmits torque between the motor 2 and the drive wheel 3 and is a generic term for a mechanism or device that transmits torque by meshing between the motor 2 and the drive wheel 3. doing. For example, in the example shown in FIG. 1, the motor 2 and the drive wheel 3 are connected via the clutch 8, the propeller shaft 9, the differential gear 10 and the drive shaft 7. In such a configuration, differential gear 10 corresponds to gear transmission mechanism 4 in the embodiment of the present invention. Although not shown, for example, a reduction gear provided on the output side of the motor 2, a planetary gear mechanism in a hybrid vehicle as described above, or a transmission provided between the driving power source 1 and the driving wheel 3 The meshing portion of the gear in the like also corresponds to the gear transmission mechanism 4 in the embodiment of the present invention.

  Further, the gear transmission mechanism 4 according to the embodiment of the present invention has a drive state in which the drive wheel 3 is driven by the motor torque of the motor 2 and a driven state in which the motor 2 is driven by the torque transmitted from the drive wheel 3 side. Between the torque transmission states are switched. When the torque transmission state is switched between such a driving state and a driven state, a predetermined gear constituting the gear transmission mechanism 4 temporarily slips, and the gear transmission mechanism 4 transmits torque. It will not be transmitted. That is, when the transmission state of torque is switched between the drive state and the driven state as described above due to the backlash that inevitably occurs in the meshing portion of the gear, the gear transmission mechanism 4 performs the gear transmission mechanism. There is a "play" in which a predetermined gear in 4 is idled to transmit no torque. In the embodiment of the present invention, a gap or a space in which such a gear transmission mechanism 4 causes idle rotation of the gear in a state in which the gear transmission mechanism 4 does not transmit torque is defined as "splay" of the gear transmission mechanism 4.

  The clutch 8 is an engagement device that selectively transmits and blocks power between the motor 2 and the drive wheel 3. In the example shown in FIG. 1, the clutch 8 includes a friction plate 8 a connected to a rotating member on the motor 2 side (for example, the rotating shaft 2 a of the motor 2) and a rotating member on the driving wheel 3 side (for example, the propeller shaft 9 A friction plate 8b connected to the Although not shown in FIG. 1, the clutch 8 has, for example, a plurality of friction plates 8a and a plurality of friction plates 8b, and is a multi-plate in which the plurality of friction plates 8a and the plurality of friction plates 8b are alternately arranged. It can also be configured by a clutch. By releasing the clutch 8, the motor 2 is disconnected from the drive system of the vehicle Ve. Further, by engaging the clutch 8, the motor 2 is connected to the drive system of the vehicle Ve. The vehicle Ve in the embodiment of the present invention may have a configuration in which the clutch 8 as described above is omitted.

  Detection unit 5 at least includes the vehicle speed of vehicle Ve, the operation amount and operation speed of an accelerator device (for example, an accelerator pedal; not shown), and the twist of the rotating member in the drive system between motor 2 and drive wheel 3 It is a generic term for sensors and devices that detect or calculate quantity etc. respectively. Therefore, the detection unit 5 detects at least a wheel speed sensor 5a for detecting the rotational speeds of the driving wheel 3 and other wheels (not shown), and an accelerator for detecting an accelerator operation amount and an accelerator operation speed of an accelerator pedal by the driver. Position sensor 5b, motor rotational speed sensor (or resolver) 5c for detecting rotational speed of motor 2, input rotational speed sensor 5d for detecting input side rotational speed of clutch 8 (for example, rotational speed of friction plate 8a), clutch Based on the output rotational speed sensor 5e for detecting the output side rotational speed of 8 (for example, the rotational speed of the friction plate 8b), for example, the rotation in the drive system based on the detection values of the wheel speed sensor 5a and the output rotational speed sensor 5e described above. The arithmetic unit 5 f and the like are provided to calculate the amount of twist of the member. Then, the detection unit 5 is electrically connected to a controller 6 described later, and outputs an electric signal according to detection values or calculation values of various sensors and devices as described above to the controller 6 as detection data.

  The controller 6 is an electronic control unit mainly composed of, for example, a microcomputer, and in the example shown in FIG. 1, mainly controls the motor 2 and the clutch 8 respectively. The controller 6 receives various data detected or calculated by the detection unit 5 described above. The controller 6 performs calculations using the various data input and data stored in advance, calculation formulas, and the like. The controller 6 outputs the calculation result as a control command signal, and controls the operation of the motor 2 and the clutch 8 as described above.

  As described above, the control device for the vehicle Ve in the embodiment of the present invention can improve the acceleration performance of the vehicle Ve without increasing the size of the motor 2 or the battery of the driving power source 1 or enhancing the performance. It is structured as follows. For this purpose, an example of control executed by the controller 6 of the vehicle Ve is shown in the flowcharts of FIGS. 2, 3, 4 and 5 below.

  The flowchart of FIG. 2 shows a basic control flow, and the control shown in the flowchart of FIG. 3 is executed as a subroutine of step S200 in the flowchart of FIG. Further, the control shown by the flowchart of FIG. 4 is executed as a subroutine of step S300 in the flowchart of FIG. Then, the control shown in the flowchart of FIG. 5 is executed as a subroutine of step S400 in the flowchart of FIG.

  The control shown in the flowchart of FIG. 2 is executed at a scene where the vehicle Ve is accelerated based on the driver's acceleration request (for example, the driver's depression operation of the accelerator pedal). Therefore, in the flowchart of FIG. 2, first, at step S100, the motor driving torque is calculated. The motor drive torque is a motor torque output from the motor 2 to generate a drive force for accelerating the vehicle Ve. For example, the motor drive torque is determined based on the required driving force determined from the conventional general vehicle speed and the accelerator opening (or the accelerator position).

  In step S200, motor torque (drive system rattle operation torque) in drive system rattle operation control is calculated. In the drive system rattle operation control, the gear drive mechanism 4 is temporarily brought into a driven state by increasing the motor torque to the negative side of the direction in which the drive wheel 3 is braked, and then the motor torque is By increasing the driving force for accelerating the vehicle Ve by closing the backlash in the gear transmission mechanism 4 and making the gear transmission mechanism 4 in a driving state.

  Specifically, the drive system rattling operation control in step S200 is performed based on the flowchart shown in FIG. In the flowchart of FIG. 3, first, at step S201, it is determined whether the change speed of the accelerator opening is larger than a constant A or not. In step S201, and in steps S203 and S205 described later, the degree of the driver's acceleration request is estimated based on the magnitude of the change speed of the accelerator opening. Here, it is determined that the driver's request for acceleration is higher as the change speed of the accelerator opening is larger.

  The constant A described above is preset as a threshold value for determining that the driver's acceleration request is at the highest level, based on, for example, results of a traveling experiment, a traveling simulation, and the like. For example, when the change speed of the accelerator opening is larger than the constant A, it is determined that the driver's acceleration request is at the highest level. In addition, when the change speed of the accelerator opening is equal to or less than the constant A, it is determined that the driver's acceleration request is at the middle level or the lowest level.

  If the change speed of the accelerator opening is larger than the constant A, and thus the determination in step S201 is affirmative, the process proceeds to step S202.

  In step S202, the constant a is set as the command negative torque, and the constant b is set as the output time of the command negative torque. The commanded negative torque is a negative side motor torque to be output to the motor 2 to bring the gear transmission mechanism 4 into a driven state in the drive system rattle operation control.

  The above constant a is preset as a maximum value or a value close to the maximum value of the negative side motor torque to be output to the motor 2 based on, for example, a result of a traveling experiment, a traveling simulation or the like. The above-mentioned constant b takes into consideration, for example, the size of rattling of gear transmission mechanism 4 obtained from the design specifications of differential gear 10, and the variation of the rattling, etc. , Is preset.

  On the other hand, when the change speed of the accelerator opening is equal to or less than the constant A, the process proceeds to step S203 when the determination in step S201 described above is negative.

  In step S203, it is determined whether the rate of change of the accelerator opening is greater than a constant B or not. As a threshold value for determining that the driver's acceleration request is at an intermediate level, for example, it is preset based on results of a driving experiment, a driving simulation, and the like. The constant B is a value smaller than the above-mentioned constant A. For example, when the change speed of the accelerator opening is equal to or less than the constant A described above and larger than the constant B, it is determined that the driver's acceleration demand is at a medium level. When the change speed of the accelerator opening is equal to or less than a constant B and greater than a constant C described later, it is determined that the driver's acceleration request is at the lowest level.

  If the change speed of the accelerator opening is larger than the constant B, the process proceeds to step S204 if the determination in step S203 is affirmative.

  In step S204, the constant c is set as the command negative torque, and the constant d is set as the output time of the command negative torque. The constant c is preset as an intermediate value of the negative side motor torque to be output to the motor 2 based on, for example, results of a traveling experiment, a traveling simulation, and the like. Specifically, the constant c is set to a median value or a value close to the median value of the constant a described above and a constant e described later. As in the case of the constant b described above, the constant d takes into consideration, for example, the size of the play of the gear transmission mechanism 4 determined from the design specifications of the differential gear 10, and the variation of the play, etc. It is preset based on the result of and so on. The constant d is basically adjusted and set to the same value as the above-mentioned constant b or a value slightly smaller than the constant b.

  On the other hand, when the change speed of the accelerator opening is equal to or less than the constant B, the process proceeds to step S205 when the determination in step S203 described above is negative.

  In step S205, it is determined whether the rate of change of the accelerator opening is greater than a constant C. As a threshold value for determining that the driver's acceleration request is at the lowest level, for example, it is set in advance based on results of a driving test, a driving simulation, and the like. The constant C is a smaller value than the constant B described above. For example, when the change speed of the accelerator opening is equal to or less than the constant B described above and greater than the constant C, it is determined that the driver's acceleration request is at the lowest level.

  If the change speed of the accelerator opening is larger than the constant C, the process proceeds to step S206 if the determination in step S205 is affirmative.

  In step S206, the constant e is set as the commanded negative torque, and the constant f is set as the output time of the commanded negative torque. The constant e is preset as a minimum value or a value close to the minimum value of the negative motor torque to be output to the motor 2 based on, for example, a result of a traveling experiment, a traveling simulation or the like. Specifically, the constant e is set to the negative motor torque when the accelerator is OFF (the accelerator opening is 0). The constant f takes into consideration, for example, the size of the play of the gear transmission mechanism 4 obtained from the design specifications of the differential gear 10 and the variation of the play, etc., similarly to the above-described constant b and constant d. It is preset based on the result of driving simulation and the like. The constant f is basically adjusted and set to the same value as the constant b and the constant d described above or to a value slightly smaller than the constant d.

  On the other hand, when the change speed of the accelerator opening is equal to or less than the constant C and thus the determination in step S205 is negative, the process proceeds to step S207.

  In step S207, the state of "no process" is set as the commanded negative torque. Also, “0” is set as the output time. In this case, it is determined that there is no driver's request for acceleration because the rate of change of the accelerator opening is equal to or less than a constant C, that is, it is not a scene for accelerating the vehicle Ve. Therefore, in this case, the command negative torque is not output.

  When the commanded negative torque and the output time in the drive system rattling operation control are set in step S202, step S204, or step S206, the process proceeds to step S208.

  In step S208, it is determined whether the control elapsed time in the drive system rattling operation control is less than the output time of the command negative torque. That is, it is determined whether or not the commanded negative torque in the drive system rattling operation control is output during the set output time in any of step S202, step S204 or step S206 described above. Be done.

  In the case where an affirmative determination is made in step S8 because the control elapsed time is less than the output time, that is, the command negative torque in the drive system rattle operation control is not yet output for the set output time. The process proceeds to step S209.

  In step S209, the commanded negative torque set in any one of step S202, step S204, or step S206 is output as the final commanded motor torque. Thereafter, the routine in the flowchart of FIG. 3 is once ended.

  On the other hand, negative determination is made in step S8 because the control elapsed time is equal to or longer than the output time, that is, the command negative torque in the drive system rattle operation control is output for the set output time. In the case, the process proceeds to step S210. In addition, also when the state of "no process" is set as command negative torque in above-mentioned step S207, and "0" is set as output time, it progresses to this step S210.

  In step S210, the state of "no process" is set as the final command motor torque. In this case, the commanded negative torque set in step S202, step S204, or step S206 is output for the output time. Alternatively, when the change speed of the accelerator opening degree is equal to or less than the constant C, it is determined that the scene does not accelerate the vehicle Ve. Therefore, in this case, no more command negative torque is output. That is, this drive system rattling operation control is ended. Thereafter, the routine in the flowchart of FIG. 3 is once ended.

  Returning to the explanation of the flowchart of FIG. 2, in step S300, the clutch release control is executed. In the clutch release control in this case, control for securing drivability of the vehicle Ve by suppressing torque fluctuation and temporary drop in torque caused by executing the drive system rattling operation control in step S200 described above. It is. As described above, in the example of the vehicle Ve shown in FIG. 1, the clutch 8 is provided between the driving power source 1 (motor 2) and the driving wheel 3. The clutch release control of step S300 is performed on the vehicle Ve having such a clutch 8. Therefore, for example, in the case of a vehicle Ve not provided with the clutch 8 as described above, the control of step S300 is omitted.

  Specifically, the clutch release control in step S300 is executed based on the flowchart shown in FIG. In the flowchart of FIG. 4, first, at step S301, it is determined whether or not drive system rattling operation control is being executed. For example, it is determined whether or not the first execution flag of drive system rattle operation control is ON. The first execution flag of the drive system rattle operation control in this case is a control flag which is set to ON when the drive system rattling operation control is executed and is set to OFF when the drive system rattle operation control is completed. .

  If negative determination is made in step S301 because the drive system rattling operation control is not being executed, for example, if the first execution flag of the drive system rattling operation control is OFF, the subsequent steps in the flowchart of FIG. This routine is ended once without executing the control of. That is, the control of step S300 in the flowchart of FIG. 2 is ended.

  On the other hand, if it is determined affirmatively in step S301 that the drive system rattling operation control is being executed, for example, the first execution flag of the drive system rattling operation control is ON, the step is positive. It progresses to S302.

  In step S302, the clutch 8 is released. Specifically, as shown in a time chart of FIG. 6 described later, the clutch hydraulic pressure supplied when engaging the clutch 8 is decreased, and the clutch 8 is in the released state. The clutch 8 is released for a predetermined period of time in accordance with the execution of the above-described clutch release control, and then engaged again. For example, the release time of the clutch 8 is set by a timer (not shown) that operates in response to the clutch release control. When the clutch 8 is released in step S302, the control routine shown in the flowchart of FIG. 4 is temporarily ended. That is, the control of step S300 in the flowchart of FIG. 2 is ended.

  Returning to the explanation of the flowchart of FIG. 2, in step S400, the gain (the degree of contribution) of the damping torque in damping control is increased. The damping control in this case is a control for suppressing torsional vibration generated in the drive system of the vehicle Ve when accelerating the vehicle Ve with the motor torque. Specifically, in the damping control performed in the next step S500, the gain of the damping torque output from the motor 2 is increased to suppress the torsional vibration.

  More specifically, the damping control in step S400 is executed based on the flowchart shown in FIG. In the flowchart of FIG. 5, first, at step S401, it is determined whether or not the execution history of the driving system rattling operation control is ON. For example, it is determined whether the second execution flag of the drive system rattle operation control is ON. When the second execution flag of the drive system rattle operation control is ON, it is determined that there is an execution history of the drive system rattle operation control. The second execution flag of the drive system rattle operation control in this case is set to ON when the drive system rattling operation control is executed, and when the acceleration of the vehicle Ve ends, or the driver steps on the accelerator pedal. It is a control flag which is set to OFF when it is returned (the accelerator opening degree is reduced).

  If negative determination is made in step S401 because the execution history of the drive system rattle operation control is not ON, for example, if the second execution flag of the drive system rattle operation control is OFF, the flowchart of FIG. This routine is ended once without executing the subsequent control in step. That is, the control of step S400 in the flowchart of FIG. 2 is ended.

  On the other hand, if the execution history of the drive system rattle operation control is ON, for example, if the second execution flag of the drive system rattle operation control is ON, it is determined affirmatively in step S401. The process proceeds to step S402.

  In step S402, it is determined whether the control elapsed time of drive system rattling operation control is shorter than a constant g. The constant g is a predetermined time required for the torsional vibration generated by the motor torque to substantially converge when the vehicle Ve is accelerated, and is preset based on, for example, results of a traveling experiment, a traveling simulation, and the like.

  That the control elapsed time of the drive system rattle operation control is equal to or greater than a constant g, that is, the control elapsed time of the drive system rattle operation control exceeds the predetermined time determined as the constant g, negative in this step S402. If it is determined, this routine is temporarily ended without executing the subsequent control in the flowchart of FIG. That is, the control of step S400 in the flowchart of FIG. 2 is ended.

  On the other hand, the control elapsed time of the drive system rattle operation control is still less than the constant g, that is, the control elapsed time of the drive system rattle operation control is still less than the predetermined time defined as the constant g. When an affirmative determination is made in step S402, the process proceeds to step S403.

  In step S403, the gain (the degree of contribution) of the damping torque is set in accordance with the driver's request for acceleration determined in step S200 described above. The damping torque in this case is a torque output from the motor 2 in order to suppress the torsional vibration in the damping control for suppressing the torsional vibration generated in the drive system of the vehicle Ve. Further, the gain of the damping torque is a control gain in this damping control, and indicates the capability of the whole control in the damping control. Alternatively, it is an index represented by the ratio of the input in the damping control to the corresponding output.

  Specifically, when the change speed of the accelerator opening degree determined in the above-described step S200 is larger than the constant A, the constant h is set as the gain of the damping torque. When the change speed of the accelerator opening is equal to or less than the constant A and larger than the constant B, the constant i is set as the gain of the damping torque. When the change speed of the accelerator opening is equal to or less than the constant B and greater than the constant C, the constant j is set as the gain of the damping torque. The magnitude relationship between the constant h, the constant i, and the constant j is “constant h> constant i> constant j”. Note that, as shown in the time chart of FIG. 6 described later, before accelerating the vehicle Ve, or at the time of steady traveling or stopping without accelerating the vehicle Ve, the damping torque is not output. The gain is zero.

  Therefore, in the control of step S403, when accelerating the vehicle Ve, the driver's acceleration request (the gain of damping torque becomes larger as the driver's acceleration request (rate of change of the accelerator opening degree) becomes larger. The gain of damping torque is increased according to the change speed of the accelerator opening). Then, when the gain of the damping torque is increased in step S403, the control routine shown in the flowchart of FIG. 5 is temporarily ended. That is, the control of step S400 in the flowchart of FIG. 2 is ended.

  The control of step S300 described above and the control of step S400 may be executed in the order of step S300 and step S400 as shown in the flowchart of FIG. Alternatively, step S300 and step S400 may be performed simultaneously or in parallel.

  Returning to the description of the flowchart of FIG. 2, in step S500, a damping torque in damping control is calculated. Specifically, the damping torque in this damping control is set according to the gain of the damping torque set in step S400 described above. For example, the damping torque in this damping control is calculated by multiplying the reference damping torque set in advance by the gain of the damping torque set in step S400. Then, the calculated damping torque is output by the motor 2. When the damping torque is output as described above in step S500, this routine is once ended.

  The damping control executed in the above-described steps S400 and S500 is not limited to the above-described control content. That is, vibration suppression control conventionally implemented may be sufficient as control for suppressing the torsional vibration which arises in the drive system of vehicle Ve.

  As described above, the behavior of the vehicle Ve when the control shown in the flowcharts of FIGS. 2, 3, 4 and 5 is executed is shown in the time chart of FIG. In the time chart of FIG. 6, before time t1 at which the accelerator opening starts to increase, the vehicle Ve is in a state where the acceleration (longitudinal acceleration) is zero or almost zero, for example, a cruising state with road load. Or, it is in the state of inertia running with the accelerator OFF. At time t1, for example, when the accelerator opening degree is increased by the driver's depression of the accelerator pedal, the control in the embodiment of the present invention is started. Then, at time t2, when the motor torque increases to the negative side corresponding to the output of the command negative torque in the drive system rattle operation control, the gear transmission mechanism 4 of the vehicle Ve is brought into the driven state. That is, before time t2, as shown in (a) of FIG. 7, the gear transmission mechanism 4 is in an unstable state where the state of rattling is not determined. On the other hand, when the motor torque increases to the negative side at time t2, as shown in (b) of FIG. 7, the gear transmission mechanism 4 drives the motor 2 by the torque transmitted from the drive wheel 3 side. To be driven.

  During the period from time t2 to time t3 (that is, the output time of the command negative torque), the negative motor torque is output. Thereafter, at time t3, when the motor torque starts to increase to the positive side, the acceleration of the vehicle Ve increases. However, in a period from time t3 to time t4, a predetermined gear in the gear transmission mechanism 4 slips due to the influence of rattling of the gear transmission mechanism 4, and the torque is not transmitted. Therefore, the acceleration of the vehicle Ve slightly increases or stagnates.

  Then, at time t4, backlash of the gear transmission mechanism 4 is clogged (that is, rattling of the gear transmission mechanism 4 occurs), and the gear transmission mechanism 4 is driven. That is, as shown to (c) of FIG. 7, the gear transmission mechanism 4 will be in the drive state which drives the driving wheel 3 by a motor torque.

  When the gear transmission mechanism 4 is in the driving state, the driving force of the vehicle Ve is increased as the motor torque is increased, and the vehicle Ve is accelerated. As described above, when the gear transmission mechanism 4 is switched from the driven state to the drive state at a stretch, the collision energy when rattling of the gear transmission mechanism 4 occurs is the rotational energy of the drive torque for generating the drive force. Is attached to Therefore, the acceleration of the vehicle Ve rapidly rises at an earlier timing and more quickly than in the conventional control (the alternate long and short dash line). Furthermore, even if compared with the normal performance limit (two-dot chain line) of the motor 2, the acceleration rises quickly beyond the performance limit. Therefore, by executing the drive system rattle operation control in the embodiment of the present invention, it is possible to generate an acceleration higher than the normal output performance of the motor 2 and accelerate the vehicle Ve. That is, the acceleration performance of the vehicle Ve can be improved without increasing the size and performance of the motor 2.

  In the case where the vehicle Ve includes the clutch 8 as in the example shown in FIG. 1 described above, the negative motor torque is output at time t2 when executing the drive system rattling operation control. The clutch hydraulic pressure is reduced and the clutch 8 is released. As a result, it is possible to suppress a torque fluctuation, a temporary drop in torque, and the like that are caused by executing the drive system rattling operation control.

  Moreover, when performing drive system rattle operation control as mentioned above, damping control for suppressing the torsional vibration in the drive system of vehicle Ve is performed collectively. For example, the gain of damping torque output in the reverse phase of the torsional vibration is increased. In the example shown in FIG. 6, the gain of the damping torque is increased at time t3 or before or after time t3 in response to the motor torque starting to increase to the positive side at time t3.

  The result of the verification experiment with a real vehicle in the case where the drive system rattle operation control is executed to accelerate the vehicle Ve as described above is shown in the time chart of FIG. After the accelerator is turned on at time t10, the acceleration increases from around time t11 to around time t12. The acceleration in the control according to the embodiment of the present invention shown by the solid line in the time chart of FIG. 8 is faster than that of the conventional control shown by the broken line in the time chart of FIG. . When these acceleration changes are converted into jerks and compared, in the control according to the embodiment of the present invention, jerk occurs approximately twice that in the conventional control. Therefore, by executing the control in the embodiment of the present invention, the driver and the occupant of the vehicle Ve experience that the acceleration performance is greatly improved as compared with the conventional case.

  Therefore, according to the control device of the vehicle Ve in the embodiment of the present invention, it occurs at the time of acceleration of the vehicle Ve without increasing the size of the motor 2 or the battery for improving the output of the driving power source 1 or enhancing the performance. The driving force that can be increased can be increased. That is, the acceleration performance of the vehicle Ve can be improved without changing the existing configuration. This means that, in other words, the motor 2 can be miniaturized if it has the same acceleration performance as the conventional one. Therefore, the mountability of the driving force source 1 including the motor 2 can be improved. Alternatively, the motor 2 can be used which is cheaper than the conventional one. As a result, the cost of the vehicle Ve can be reduced.

  Further, when accelerating the vehicle Ve by the motor torque, together with the drive system rattling operation control as described above, the gain of the damping torque output by the motor 2 to suppress the torsional vibration generated in the drive system at the time of acceleration (contribution Degree) is increased. For example, the gain of damping torque is increased according to the driver's acceleration demand so that the gain of damping torque also increases as the driver's acceleration demand increases. Therefore, when accelerating the vehicle Ve, it is possible to suppress the occurrence of shock or discomfort caused by the torsional vibration in the rotating member of the drive system. As a result, the drivability of the vehicle Ve in the embodiment of the present invention can be improved.

  DESCRIPTION OF SYMBOLS 1 ... Drive force source, 2 ... Motor (drive force source) 2a ... Rotation shaft of 3 (motor), 4 ... Drive wheel, 4 ... Gear transmission mechanism, 5 ... Detection part, 5a ... Wheel speed sensor, 5b ... Accelerator position sensor , 5c: motor rotational speed sensor (resolver), 5d: input rotational speed sensor, 5e: output rotational speed sensor, 5f: arithmetic unit, 6: controller (ECU), 7: drive shaft, 8: clutch, 8a, 8b ... Friction plate, 9: propeller shaft, 10: differential gear (gear transmission mechanism), Ve: vehicle (electric vehicle).

Claims (1)

An electric vehicle comprising at least a drive power source having a motor, a drive wheel, a gear transmission mechanism transmitting torque between the drive power source and the drive wheel, and a controller controlling motor torque output from the motor In the controller of
The gear transmission mechanism switches the torque transmission state between a driving state in which the driving wheel is driven by the motor torque and a driven state in which the motor is driven by the torque transmitted from the driving wheel side. The gear has a play that causes a predetermined gear in the gear transmission to idle and not transmit torque.
The controller
When accelerating the electric vehicle according to the driver's acceleration request,
After the gear transmission mechanism is temporarily brought into the driven state by increasing the motor torque to the negative side of the direction in which the drive wheel is braked, the motor torque is adjusted in the positive direction to drive the drive wheel. By increasing to the side, the rattling is eliminated and the gear transmission mechanism is brought into the drive state to increase the driving force for the acceleration;
A control device for an electric vehicle, wherein a gain of damping torque output by the motor is increased to suppress a torsional vibration generated by increasing the motor torque to the positive side.

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