WO2007110967A1 - Vehicle motion control device - Google Patents

Abstract

To rapidly converge the vibration of a vehicle in the yaw direction occurring after the vehicle urgently avoids an obstacle. For the purpose, this vehicle motion control device is so structured that rear wheels (6RL, 6RR) are driven independently of each other by two motors (4L, 4R). The yaw moment of the vehicle is controlled by alternately providing the torques reverse to each other to right and left motor-driven wheels, and thereby, the vibration of the vehicle in the yaw direction can be damped.

Description

 Specification

 Vehicle motion control technology

 The present invention relates to an automobile motion control apparatus, and relates to a configuration and control technology of a device that improves the motion performance and safety of a vehicle. Background art

 Conventionally, as a configuration for improving the running stability of a vehicle, a configuration in which the rear wheels are independently driven by two hydraulic motors has been known. As an example, there is an apparatus described in Japanese Patent Application Laid-Open No. 7-30 4 3 4 6. To explain this, the right and left independent hydraulic pump Z motor can be used to apply opposite torques to the left and right rear wheels, and the vehicle moment can be controlled to control the vehicle when turning the vehicle. Stability was improved. In addition, fuel efficiency has been improved by regenerating braking energy via hydraulic energy. The hydraulic motor may be an electric motor, and the braking energy in this case was regenerated by a battery or capacitor. Disclosure of the invention

Japanese Patent Application Laid-Open No. 7-30 4 3 4 6 discloses a system configuration, but does not provide a detailed description of the control method. The device described in the above publication is aimed at improving the steering stability when turning the vehicle, but it cannot be said that sufficient consideration is given to effectively reducing the vehicle's lateral vibration. In particular, the effect of one-way vibration that occurs after the vehicle urgently avoids an obstacle is effective. Consideration about the reduction was not enough.

 In addition, the above publication does not describe in detail the electric circuit when using the electric motor. In particular, when an ordinary lead battery is used for power regeneration, the chemical reaction inside the battery is necessary for power regeneration, so the response is low, and the motor braking torque for a short time when reducing the vehicle vibration in the vehicle direction is low. There was a problem that it was not suitable for regeneration.

 An object of the present invention is to provide a vehicle motion control device capable of more quickly converging the vibration in the direction of emergency after emergency avoidance (hereinafter referred to as “yo-damping”) in addition to improving the steering stability during turning. Another object of the present invention is to provide a vehicle motion control device that can efficiently regenerate motor braking torque during jordanbing and can be driven with low power consumption.

 In order to achieve the above object, the vehicle motion control device of the present invention is a vehicle motion control device for an automobile in which front wheels or rear wheels are driven by engine power, and includes two non-drive-side wheels that are not driven by engine power. The motor is configured to drive the left and right wheels independently of each other, and by controlling the vehicle's momentum by giving a difference in the drive torque of the left and right wheels of the motor drive, it is controlled to attenuate the vibration in the vehicle's direction. It is configured to have a controller to be used.

 At this time, it is preferable to give a difference in the drive torque of the left and right wheels of the motor drive by alternately applying opposite torques to the right and left wheels of the motor drive.

In addition, the controller uses the steering steering angle input by the driver, throttle opening, yorate acting on the vehicle, lateral acceleration of the vehicle, wheel speed, etc. The motion of the normative rate that is the motion and the normative side slip angle is calculated, and the actual yore rate and the side slip angle are equal to the normative rate and the normative side slip angle. It may be configured to calculate the amount of moment.

 Also, the controller may be configured to increase the gain of control based on the yorate according to the steering steering angle.

 As a result, the vehicle behavior after emergency avoidance of obstacles in particular is stabilized, and a highly safe vehicle is realized.

 In addition, two motors are used as AC motors, two inverters that drive the motors, and a generator that supplies power to the inverters, and two inverter housings. It is advisable to configure so that the power lines between the two inverters are shortened by integrating or arranging them closely.

 Furthermore, when the opposite direction torque is alternately applied to the left and right wheels of the motor drive to attenuate the vibration in the vehicle direction, the regenerative current generated in the brake motor is sent to the drive motor. It is advisable to perform power regeneration so that only the insufficient power is supplied from the generator.

 As a result, it is possible to reduce the power required to attenuate the vibration in the direction of the current direction.

 In the vehicle motion control device of the present invention, the two motors are field-controlled motors, and a generator is provided for supplying electric power to the motors. It may be configured to control the motor moment by controlling the motor torque by controlling the field of each motor.

 As a result, there is no need to load a battery and the cost can be reduced. In addition, the back electromotive force during high rotation can be suppressed by the field weakening field, so that the motor drive voltage can be suppressed low.

Furthermore, when a large braking torque is generated in the motor, the controller shorts the motor and controls the motor field to control the motor. It may be configured to control the braking torque.

 As a result, a large braking torque can be controlled smoothly. Brief Description of Drawings

 FIG. 1 is a diagram (FF vehicle) showing an embodiment of a vehicle motion control device of the present invention.

 FIG. 2 is a diagram showing a configuration of a controller in the vehicle motion control device of the present invention.

 FIG. 3 is a diagram for explaining the effect of the vehicle motion control device of the present invention. FIG. 4 is a diagram (FR car) showing an embodiment of the vehicle motion control device of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

 Embodiments according to the present invention will be described below with reference to the drawings.

 FIG. 1 shows an embodiment of a vehicle motion control device of the present invention. This is an example in which the vehicle motion control device of the present invention is applied to a so-called FF vehicle in which the engine 1 is in the front part of the vehicle and the front wheels 6 FL and 6 FR are driven by engine power.

The left and right rear wheels 6 RL and 6 RR are configured to be driven independently by left and right AC motors 4 L and 4 R. The motor is driven by two inverters 3 L and 3 R, respectively. The all evening 2 is driven by the engine 1 to generate electric power, and the generated electric power is stored in the battery 5 and then supplied to the two inverters 3 L and 3 R. Note that OL evening 2 is provided for power supply to the motor separately from the normal battery that drives the star injector. It is controlled by the controller so that only a certain amount is generated. The battery 5 is not necessarily required, and the power generated by the alternative 2 may be directly supplied to the inverters 3 L and 3 R. Further, the AC motor 4 L and 4 R may be either a wound field type or a permanent magnet field type as long as a field weakening is possible.

 FIG. 2 shows a configuration example of a controller in the vehicle motion control device. Based on the driver's steering operation and vehicle speed, the controller obtains the standard vehicle motion intended by the driver and controls the motor torque so that the actual vehicle motion does not deviate from the standard vehicle motion. It controls the movement.

Specifically, the standard steering speed and the standard lateral slip angle are calculated from the information of the steering angle, throttle opening, brake operation amount, high rate sensor, lateral acceleration sensor, and wheel speed sensor. The vehicle is controlled so that there is no deviation from the slip angle. The normative rate and the normative slip angle are calculated using a linear vehicle motion model. In other words, the vehicle rate calculated from the linear model and the side slip angle indicate the vehicle movement intended by the driver, and the vehicle is in an unstable state (nonlinearity) when the actual value deviates from the reference value. The torque is controlled and the motor torque is controlled. In addition, in vehicles equipped with electronically controlled brakes and electronically controlled throttles that are independent for each wheel, the brakes and throttle opening may be controlled as needed in addition to controlling the motor torque. Especially for brakes that can be controlled independently for each wheel, the brake moment can be controlled by the brake itself, so a wider range of momentum control becomes possible by combining with momentum control by motor torque control. Since it is possible to brake the motor itself, the brakes 8 L and 8 R are arranged only on the front wheels in the embodiment shown in Fig. 1. Next, the effect of the vehicle motion control apparatus of this embodiment will be described with reference to FIG. Here, a scene is shown in which the preceding vehicle where the vehicle is an obstacle is urgently avoided. In conventional vehicles, the steering steering angle is set to 0 after emergency avoidance, that is, the vehicle's vibration in the direction of the head does not converge even though it is returned to the straight-ahead state, resulting in a very unstable and dangerous state. It has been known. On the other hand, in the car of this embodiment, the vehicle speed can be freely controlled by the left and right independent drive mode of the rear wheels, so that the vibrations after emergency avoidance can be quickly converged (case) 1, 2). Specifically, the reverse vibration is applied to the left and right rear wheels of the motor drive alternately according to the vibration of the current, thereby converging the vibration. This is automatically realized by the controller configuration shown in Fig. 2.

 In addition, in this embodiment, the effective logic damping is performed by switching the control logic at the time of the dumping and other times (when the vehicle is turning). For example, in this embodiment, when the steering angle is almost zero and the yorate exceeds a certain reference value, it is judged that yo vibration has occurred, and the worate feedback gain is increased (case 2). As a result, the Choo vibration can be converged more quickly. In the embodiment shown in FIG. 3, the feedback gain is switched on and off. However, the feedback gain may be continuously changed in accordance with the steering angle and the short rate.

 As described above, the handling stability of the vehicle can be improved, and particularly the behavior of the vehicle after emergency avoidance of an obstacle can be stabilized, so that a highly safe vehicle can be provided.

Next, the flow of electricity during jor damping will be described using Fig. 1. As shown in Fig. 1, one damping of the rear wheels is alternately driven and the other is braked alternately. At this time, the regeneration that occurs in the brake side Power can be saved by supplying current to the drive-side motor and supplying only insufficient power from the battery 5. Supply directly). In the vehicle motion control apparatus of this embodiment, the power line of the inverter is shortened by integrating the two inverter 3 L and 3 R housings, or by placing them close to each other. Power regeneration is made more efficient.

 In the vehicle motion control apparatus of this embodiment, by controlling the solar power 2 so that only the power required by the motor is generated, no battery storage means such as a capacitor is required, and the cost of the system is low. Is possible. Specifically, the generated voltage is arbitrarily controlled by controlling the field current in the evening.

 Here, when the vehicle is driven at high speed in the electric motor, a large counter electromotive voltage is generated in the motor, and current must not be input to the motor unless a voltage high enough to resist this is generated in the evening. There is a problem. Therefore, in the vehicle motion control device of this embodiment, the motor 4L and 4R are of the field control type, and the back electromotive force is suppressed by performing field weakening at high revolutions, and the motor output is reduced even at low voltages. It is configured so that it can be put out. As a result, the motor output range is secured up to the high speed range while reducing system costs.

Next, for example, when the vehicle is suddenly braked with the morning braking torque, the vehicle motion control device of this embodiment is configured to easily obtain a large braking torque by short-circuiting the input terminal of the motorcycle. Yes. However, if the motor is suddenly short-circuited, the deceleration shock is large, and the driver may feel uncomfortable or the vehicle may become unstable. Therefore, by performing field weakening of the motors 4 L and 4 R in accordance with the short circuit, the motor efficiency is lowered, so that the braking torque is reduced and the deceleration shock can be softened. sand That is, according to the configuration of the present embodiment, it is possible to smoothly control a large braking torque.

 FIG. 4 shows an example in which the vehicle motion control device of the present invention is applied to a so-called FR vehicle in which the engine 1 is in the front part of the vehicle and the rear wheels 6 R L and 6 R R are driven by engine power. Here, the battery is omitted. In this case, contrary to the embodiment of FIG. 1, the front wheels 6 F L and 6 F R are

It is configured to drive at 4R, with brakes 7 only on the rear wheels and 7R. Although there is a difference between the front and rear wheels of the motor drive wheel, it is possible to control the vehicle moment by applying a torque difference to the two left and right motors with either method. The same effect as the embodiment of FIG.

 However, if a torque difference is applied to the left and right front wheels at 4 L and 4 R, reaction force may be transmitted to the driver through the steering as a sense of incongruity, which may reduce the merchantability. In response to this, an electronically controlled steering wheel that can control the steering angle separately from the driver input is provided. Can not be transmitted to the driver. It should be noted that in a vehicle equipped with a steering gear such as this, the left and right independent drive motors, brakes, steering, and throttle can be controlled in an integrated manner, resulting in extremely high motion performance and safety. Can realize excellent vehicles.

According to each of the above-described embodiments of the present invention, it is possible to improve the steering stability during turning by controlling the vehicle moment, and in particular, it is possible to quickly converge the jo-direction vibration after emergency avoidance. Therefore, a highly safe vehicle can be provided. In addition, motor braking when converging vibrations Since the torque can be regenerated efficiently, a power-saving vehicle motion control device can be provided.

Claims

0 Scope of request  1. In a vehicle motion control device for an automobile in which front wheels or rear wheels are driven by engine power, the non-drive-side wheels that are not driven by engine power are configured to be driven independently by the left and right wheels in two modes. A vehicle motion control device comprising a controller for controlling the vehicle moment by giving a difference to the drive torque of the right and left wheels for evening driving, thereby damping the vibration in the vehicle direction.  2. The vehicle motion control device according to claim 1, wherein torques in opposite directions are alternately applied to the left and right wheels of the motor drive to give a difference in the drive torque of the left and right wheels of the motor drive. A vehicle motion control device characterized by controlling the vehicle moment.  3. The vehicle motion control device according to claim 1, wherein the controller includes a steering steering angle input by a driver, a throttle opening, a normal rate acting on the vehicle, and a lateral acceleration of the vehicle. Based on information such as the wheel speed, the normative velocity and the normative side slip angle, which are the target movements intended by the driver, are calculated. A vehicle motion control device configured to calculate the amount of moment given to the motor so as to be equal to a slip angle.  4. The vehicle motion control device according to claim 3, wherein the controller increases a gain of control based on the correct rate in accordance with the steering steering angle. 5. The vehicle motion control device according to claim 1, wherein the two motors are defined as AC motors, two inverters driving the motors, and power generation for supplying power to the inverters. And two invar evenings by integrating or arranging the two inver evening housings together. A vehicle motion control device characterized in that the power line is shortened. 6. The vehicle motion control device according to claim 2, wherein when the left and right wheels of the motor drive are alternately applied with mutually opposite torques to attenuate the vibration in the vehicle direction, the motor on the braking side A vehicle motion control device that performs power regeneration by sending a regenerative current that is generated to a drive side motor so that only insufficient power is supplied from the generator.  7. The vehicle motion control device according to claim 1, wherein the two motors are field control motors, and a generator is provided to supply power to the motors, and the controller includes the controller A vehicle motion control device that controls a motor torque by controlling a motor torque by controlling a power generation amount of a generator and the two motor fields.  8. The vehicle motion control device according to claim 7, wherein when the motor generates a large braking torque, the controller short-circuits the motor and controls the field of the motor. A vehicle motion control device that controls braking torque in the evening.