JP5849708B2 - Vehicle driving force control device - Google Patents

Description

  The present invention relates to an apparatus for controlling a driving force of a vehicle, and more particularly to an apparatus for controlling a driving force in relation to a steering characteristic in a turning state and for controlling a driving force in order to prevent a side slip.

  The acceleration / deceleration of the vehicle is basically performed by increasing or decreasing the output of a driving force source such as an engine by depressing the accelerator pedal or returning the depressed accelerator pedal. On the other hand, since the ground contact point where the tire contacts the road surface is off the center of gravity of the vehicle body, the lateral force on the tire changes according to the change in driving force when turning, and the yaw moment acting on the vehicle body also changes. Therefore, the turning performance (turning characteristics) changes according to the driving force.

  In addition, when turning a vehicle, various driving functions such as changing the steering characteristics by controlling the driving force and braking force to ensure vehicle stability, and distributing the braking force to the front, rear, left and right wheels to prevent skidding of the tires, etc. A control device is disclosed.

  For example, Patent Document 1 discloses vehicle stability control that controls braking force so as to maintain yaw stability during curve deceleration control that controls braking force so that the vehicle can pass a curve at an appropriate vehicle speed, that is, skid prevention control. Is determined, a technique for switching from curve deceleration control to vehicle stability control and adding a control amount (target value or actual value) for curve deceleration control to the control amount of vehicle stability control is described. In addition, when the actual values are added, the added value is gradually decreased toward zero after the addition.

  Patent Document 2 includes an overspeed suppression device that predicts a virtual line and performs deceleration control, and a vehicle behavior control device based on a yaw moment. When both the overspeed control and the vehicle behavior control are operated, the overspeed control is performed. It is described that the deceleration is maintained.

  Patent Document 3 includes a device that executes a turning control mode that generates substantially the same braking / driving force on the left and right wheels and a side-slip prevention control mode that generates different braking / driving forces on the left and right wheels. It is described that when the command is smaller than a predetermined value, the turning control mode is selected, and when the yaw moment command is larger than the predetermined value, the skid prevention control mode is selected.

JP 2009-173104 A JP 2007-46525 A JP 2010-162911 A

  However, in the apparatus described in Patent Document 1, no consideration is given to the case where the side slip prevention control is executed during the turning control in which the steering characteristic is changed by correcting the driving force, and the side slip prevention control is executed during the turning control. When doing so, hunting occurs in the driving force control, and there is a possibility that the correction value of the driving force by the side slip prevention control is insufficient.

  Further, in the device described in Patent Document 2, although the case where the overspeed control device and the vehicle behavior control device are operated together is considered, in the case where both the turning control and the side slip prevention control are executed, the vehicle However, it was not designed to achieve both the turning stability and the prevention of skidding.

  Furthermore, in the apparatus described in Patent Document 3, the first mode for generating substantially the same braking / driving force on the left and right wheels and the second mode for generating different braking / driving forces on the left and right wheels are the yaw moment commands. It operates according to the size of the vehicle, and does not distribute different loads and braking / driving forces to the left and right wheels during execution of the first mode, that is, stops the second mode, turning control and skid prevention The case where the control and the control are executed together was not considered.

  The present invention has been made paying attention to the above technical problem, and even when both turning control and vehicle stabilization control are executed, the turning performance and the prevention of skidding, etc. during turning are provided. It is an object of the present invention to provide a vehicle driving force control apparatus that controls driving force so as to achieve both vehicle stabilization.

Invention, a side slip prevention means that to adjust the longitudinal force of each wheel so suppress skidding of vehicles, main obtained based on the acceleration and deceleration request according to claim 1 in order to achieve the above object A driving force control apparatus for a vehicle, comprising: a turning control unit that corrects the driving force so that the vehicle turns stably. The driving force correction control by the skid prevention unit and the driving force correction by the turning control unit. control and are executed together, and wherein when the driving force correction amount by the turning control means is a correction amount to reduce the required driving force, while being configured to hold the driving force correction amount by the turning control means The driving force correction amount, which is the amount by which the driving force is changed by the control of the skid prevention means, is a correction amount that reduces the required driving force, and is the absolute value of the driving force correction amount by the skid prevention means. There when in the state of decreasing is characterized in that it is configured so as to gradually reduce the absolute value of the driving force correction amount by the turning control means.

The invention according to claim 2, in addition to the invention according to claim 1, the driving force correction amount by the anti-skid means is a case where the correction amount to reduce the required driving force, and the change in steering the steering angle When the rate of change and the rate of change of the required driving force are both smaller than a predetermined value or when the rate of change is both zero, the absolute value of the driving force correction amount by the skid prevention means is reduced. A driving force control apparatus for a vehicle characterized by the above.

In the invention according to claim 3, in addition to the invention according to claim 1, when the driving force correction amount, which is the amount by which the driving force is changed by the control of the skid prevention means, is a correction amount for reducing the required driving force, and when in the state in which the absolute value of the driving force correction amount by the anti-skid device is reduced, when gradually decreasing the absolute value of the driving force correction amount by the turning control means, driven by pre Symbol swing control means An absolute value of the force correction amount is gradually decreased until it becomes smaller than the predetermined value, and the absolute value of the force correction amount is not larger than the predetermined value. is there.

  According to the first aspect of the present invention, when the turning control means and the skid prevention control means are operated together, it is possible to prevent mutual interference with the control system, ensuring vehicle stability and preventing the driver from feeling uncomfortable. Can be made compatible. Further, it is possible to prevent the occurrence of torque fluctuation caused by stopping the turning control, there is no possibility of causing fluctuation of output torque not accompanying the accelerator pedal operation, and it is possible to prevent the driver from feeling uncomfortable due to the output torque. .

  According to the second aspect of the present invention, both the turning control and the skid prevention control can be performed, and the required driving force is not reduced more than necessary for the turning control, so that the output torque deviates from the required driving force. This can reduce the uncomfortable feeling given to the driver. In addition, a driving force correction amount can be newly output at the next corner to change the longitudinal acceleration of the vehicle and improve the turning performance.

  According to the invention of claim 3, since the required driving force is not reduced more than necessary for the prevention of skid, it is possible to reduce the magnitude that the output torque deviates from the required driving force, and to give the driver a sense of incongruity. Can be reduced.

  According to the invention of claim 4, when the control in the skid prevention means is completed from the state in which the turning control means and the skid prevention means are mutually operated, the driving force correction amount by the turning control means is zero. There is no difference between the driver's required driving force and the actual output torque, and the driver does not feel uncomfortable. In addition, it is possible to prevent the actual output torque from increasing momentarily when the driving force correction amount by the turning control means is canceled, thereby deteriorating the stability of the vehicle.

It is the figure which showed an example of the processing flowchart of the driving force control performed by the driving force control apparatus which concerns on this invention. 3 is a time chart schematically showing changes in driving force corrected by a driving force control device in accordance with vehicle steering and acceleration / deceleration. It is the figure which simplified and illustrated the drive system and control system of the vehicle which can be made into object by this invention. It is the time chart which showed roughly the change of the driving force controlled when a skid prevention device does not operate. It is the time chart which showed roughly the change of the driving force controlled when turning control is stopped immediately when a skid prevention device operates. 7 is a time chart schematically showing changes in driving force controlled when turning control is stopped after holding a driving force correction amount in turning control when the skid prevention device is operating.

  The present invention can control the driving force in order to ensure the stability of the vehicle in a state where the driving force is controlled so as to achieve the target turning state, and can achieve both turning performance and vehicle stability. In this way, the driving force is controlled. In particular, it is a device configured to perform driving force control that better reflects the driver's intention to accelerate or decelerate or turn. Therefore, in addition to being able to control the driving force based on the acceleration / deceleration operation such as the driver's accelerator operation, the vehicle that can be the subject of the present invention can control the driving force without depending on the acceleration / deceleration operation. It is a configured vehicle. In addition to controlling the braking force based on the driver's braking operation, the vehicle is configured to be able to control the braking force without depending on the braking operation.

  The driving force source may be an internal combustion engine (engine), an electric motor, or a combination of any of these and an automatic transmission, or a hybrid drive device combining an internal combustion engine, an electric motor, and a transmission mechanism. May be. Further, the control of the driving force, particularly the control for reducing the driving force, may be executed by controlling the braking force of the wheels.

  FIG. 3 is a block diagram showing the configuration and control system of a vehicle that can be targeted by the present invention. The vehicle shown in FIG. 3 is an example of a rear wheel drive vehicle (FR). Each of the front, rear, left and right wheels 1 is provided with a brake 2 that can be individually controlled. These brakes 2 are configured to be controlled by a conventionally known system such as an anti-lock brake system (ABS) or a vehicle stabilization control system (VSC). Therefore, the brake 2 of each wheel 1 increases the braking force regardless of the pedal operation by the driver or conversely reduces the braking force when the driving force is excessively applied or the braking force is too large. .

  A driving force source 3 composed of an internal combustion engine, an electric motor, or the like is connected to the left and right rear wheels 1 through a differential, and the speed ratio is changed by changing the output of the driving force source 3 or in the power transmission system. Is configured to control the driving force. As the driving force source 3, at least one of an internal combustion engine or an electric motor can be used, or both the internal combustion engine and the electric motor can be mounted as the driving force source 3 as a hybrid vehicle. For example, when an internal combustion engine such as a gasoline engine, a diesel engine, or a natural gas engine is mounted on the vehicle as the driving force source 3, various transmissions such as a manual transmission and an automatic transmission are provided on the output side of the driving force source 3 ( Not shown) is used. Further, when an electric motor is mounted on the vehicle as the driving force source 3, an electric storage device (none of which is shown) such as a battery or a capacitor is connected to the electric motor via an inverter.

  A controller 4 that is an electronic control device for controlling the power output from the driving force source 3 is provided. The controller 4 is mainly composed of a microcomputer, and uses data stored in advance or data input from the outside to process data according to a program prepared in advance, and the result is a control command. The signal is output to the driving force source 3 as a signal. The controller 4 is connected to the driving force source 3 and is capable of automatically controlling the driving force of the vehicle generated by the rear wheels 1 as driving wheels by controlling the output of the driving force source 3. It has become. The controller 4 is connected to each brake 2 via an actuator (not shown) and controls the operation of the brakes 2. Accordingly, the vehicle braking force generated by each wheel 1 can be automatically and individually controlled by the controller 4.

  The controller 4 is configured to receive detection signals from various sensors in various parts of the vehicle and information signals from various in-vehicle devices. For example, the lateral acceleration sensor 5 that detects acceleration in the vehicle axle direction, that is, the lateral direction (lateral acceleration), the steering angle sensor 6 that detects the steering angle of the steering wheel, and the yaw rate sensor 7 that detects the yaw rate of the vehicle have detected. The value is input to the controller 4 as a detection signal. These sensors 5, 6 and 7 are sensors constituting a system such as the above-described vehicle stabilization control system (VSC), and are existing devices in a vehicle including the system. Further, as sensors (not shown), an accelerator sensor that detects the depression angle (or depression amount or accelerator opening) of the accelerator pedal, a brake sensor that detects the depression angle (or depression amount or brake opening) of the brake, and each drive wheel 1 is a detection signal from a wheel speed sensor that detects the rotational speed (wheel speed) of 1, a longitudinal acceleration sensor that detects longitudinal acceleration (longitudinal acceleration) of the vehicle, a torque sensor that detects output torque of the driving force source 3, and the like. May be input to the controller 4.

  The driving force control device according to the present invention mounted on a vehicle having the above-described configuration is configured to obtain a required driving force based on operation of an acceleration / deceleration operation mechanism such as an accelerator pedal from various sensors while the vehicle is turning. To perform the turning control for correcting the actual turning state based on the detection signal to be a predetermined target turning state, and the side slip prevention control for correcting to prevent the side slip particularly in order to ensure vehicle stability. It is configured.

  The turning control can control the steer characteristic and the stability factor, and in particular, is control for improving the turning performance of the vehicle by improving the steer characteristic during turning. For example, the vehicle speed and the friction coefficient of the road surface are estimated from the wheel speed of each wheel 1 detected by the wheel speed sensor, and based on the vehicle speed, the friction coefficient of the road surface, the steering angle detected by the steering angle sensor, etc. The target steer characteristic to be set is set, and the actual steer characteristic of the vehicle is controlled to follow the target steer characteristic.

  Specifically, the actual steering characteristic of the vehicle can be brought close to the target steering characteristic by controlling the yaw rate of the vehicle by changing the driving force and braking force of the vehicle, that is, performing so-called turning improvement control. . When controlling the yaw rate of a vehicle, the target yaw rate of the vehicle at that time is obtained based on information such as the vehicle speed, the steering angle, and the wheel base from the center of gravity of the vehicle, and the actual yaw rate (actual yaw rate) of the vehicle is the target. For example, the yaw rate of the vehicle can be controlled by performing the above-described turning performance improvement control so as to approach the yaw rate. Further, the yaw rate of the vehicle can be controlled by increasing or decreasing the torque corresponding to the correction amount with respect to the driving force generated in each driving wheel 1 or the braking force applied to each wheel 1. . As described above, the control for setting the target yaw rate and causing the actual yaw rate of the vehicle to follow the target yaw rate is disclosed in various documents and is well known.

  In addition, the turning control can be performed by controlling the driving force so that the stability factor matches as much as possible a predetermined target value. Here, the stability factor is a physical quantity that can be obtained based on the wheel base from the center of gravity of the vehicle, the steering angle, the vehicle speed, the lateral acceleration, the lateral jerk, the yaw rate, the tire stiffness, etc., and is an index representing the turning characteristics of the vehicle. It is. This stability factor indicates a characteristic in a state where the radius is constant, that is, the vehicle is traveling in a steady circle. It is well known in various literatures that the stability factor can be extended to a state where longitudinal acceleration occurs.

  On the other hand, the skid prevention control is a control that prevents a skid of the wheel in a rotating state where the wheel is not facing in the traveling direction of the vehicle, that is, a so-called slip angle, due to a sudden steering wheel operation or traveling on a slippery road surface. is there. In order to maintain the lateral stability of the vehicle, the braking force applied to the wheel 1 by the brake 2 and the output of the power source 3 are controlled to exceed the grip limit between each wheel 1 and the road surface when turning. It makes things difficult. For example, when the steering wheel does not turn even when the steering wheel is operated and steered at an overspeed, the skid prevention device reduces the output of the power source 3 and applies a braking force by the brake 2 to each wheel 1 so that the wheel skids. When started, a braking force is generated on the front outside wheel 1 to control the behavior of the vehicle.

  The vehicle that is the object of the present invention is configured to execute both the turning control for controlling the actual turning state to be the target turning state and the side slip prevention control for preventing the side slip of the wheel. Therefore, these controls may overlap. The driving force control apparatus according to the present invention executes the driving force control in such a case as described below.

  FIG. 1 is a flowchart illustrating an example of a driving force control process performed by the driving force control apparatus according to this embodiment. The routine shown here is repeatedly executed every predetermined short time. FIG. 2 is a time chart showing a change in the driving force correction amount when the driving force control process in FIG. 1 is executed, and the turning control is performed according to the change in the required driving force due to the steering angle and the accelerator operation. 6 shows the control of the driving force by the control of the driving force, the control of the driving force by the side slip prevention control, and the final command torque. Therefore, FIG. 1 can also be said to be a processing flow for calculating the driving force correction amount Fctrl for turning control in the driving force control device of this embodiment. The output driving force correction amount Fctrl is illustrated as an example in FIG. 3 is a time chart of a change in a correction amount by turning control exemplified in FIG.

  The driving force control apparatus in this embodiment stores the driving force correction amount Fctrl of the turning control output in the previous driving force control process in the storage unit as the driving force correction amount Fctrl (n−1) (step S101).

  The driving force correction amount described here is a control amount or a change amount for correcting a required driving force according to an acceleration / deceleration request operation such as a pedal. The driving force correction amount takes positive and negative values. The correction amount that reduces the required driving force expresses that the driving force correction amount is a negative value, and the correction amount that increases the required driving force means that the driving force correction amount is a positive value. Express. Furthermore, when the magnitude of the driving force correction amount is described, it is expressed by an absolute value. A state in which the absolute value of the driving force correction amount decreases means that the amount to be corrected becomes small, and a state in which the absolute value of the driving force correction amount increases means that the amount to be corrected becomes large. To do. The driving force correction amount includes a driving force correction amount Fctrl for turning control and a driving force correction amount Fvsc by the skid prevention device. That is, the final command torque output by the driving force control device for controlling the driving force is corrected by the driving force correction amount Fctrl for turning control and the driving force correction amount Fvsc by the skid prevention device. It is a thing.

  After storing the correction amount Fctrl (n-1) by the previous turning control in step S101, the target turning state of the vehicle calculated by the controller 4 based on the information input from various sensors, at least the steering angle and the yaw rate. A driving force correction amount Fctrl, which is a driving force correction amount in the turning control, is calculated from the difference from the actual turning state estimated from the information including (step S102). When the driving force correction amount Fctrl in the turning control is calculated, it is determined whether or not the skid prevention device is operated (step S103). When it is determined that the skid prevention device is not operating as a result of the above-described operation presence / absence determination (No in step S103), the driving force correction amount Fctrl calculated in step S102 is output as a correction amount to be output in the current turning control. Then, the current driving force control process is terminated, and the routine returns to the routine repetition process.

  On the other hand, if it is determined that the skid prevention device is operating as a result of the above-described operation presence / absence determination (Yes in step S103), the driving force correction amount Fctrl (n−1) stored in the storage unit in step S101 is driven. It is determined whether or not the correction amount reduces the force (step S104).

  When the driving force correction amount Fctrl for turning control is not a negative value as a result of the positive / negative discrimination, that is, when the driving force correction amount Fctrl is a positive value or zero (No in step S104), the driving force is corrected by turning control. And the driving force correction amount Fctrl calculated in step S102 is set to zero (step S108), and the driving force correction amount Fctrl = 0 is output as a correction amount to be output in the current turning control (step S109). ), The current driving force control process is terminated, and the routine returns to the routine repetition process.

  On the other hand, if the result of the positive / negative determination is that the driving force correction amount Fctrl for turning control is a negative value (Yes in step S104), the current driving force correction amount is calculated from the driving force correction amount Fctrl calculated in step S102. The previous driving force correction amount Fctrl (n−1) stored in the storage unit in step S101 is replaced, and the replaced driving force correction amount Fctrl (n−1) is held as the current driving force correction amount. (Step S105). That is, in step S105, the current driving force correction amount Fctrl = Fctrl (n−1) is held. Note that the driving force correction amount in the turning control held in step S105 is held regardless of the magnitude of the absolute value. For example, even if the absolute value of the driving force correction amount Fctrl for turning control is a small value, it is held in step S105.

  In addition, the driving force control device determines whether or not the absolute value of the driving force correction amount Fvsc, which is the driving force correction amount in the skid prevention device, is decreasing (step S106). The decrease determination is performed to relieve the state in which the output of the driving force source 3 is suppressed to prevent the side slip, that is, whether or not the amount of decrease in the driving force with respect to the required driving force for preventing the side slip is reduced. To do.

  As a result of the decrease determination, if the absolute value of the driving force correction amount Fvsc in the skid prevention device is not in a decreasing state (No in step S106), the driving force correction amount Fctrl (n−1) that is the value held in step S105 is obtained. Then, it outputs as a correction amount to be output in the current turning control (step S109), ends the current driving force control process, and returns to the routine repetition process.

  On the other hand, if the absolute value of the driving force correction amount Fvsc in the skid prevention device is decreasing as a result of the decrease determination (Yes in step S106), the absolute value of the driving force correction amount by turning control is gradually decreased. Control to go to zero. For example, a predetermined value A that is a positive value is added to the driving force correction amount Fctrl (n−1) that is a negative value held in step S105, and the added value is used as the current driving force correction amount Fctrl. (Step S107). That is, in step S107, the current driving force correction amount [Fctrl = Fctrl (n−1) + A] is set. In other words, the absolute value of the driving force correction amount Fctrl (n−1) held in step S105 is subtracted from the absolute value of the predetermined value A, and is a negative value that becomes the absolute value of the subtracted value. The correction amount is the current driving force correction amount Fctrl. The predetermined value A may be a constant value, and the driving force correction amount Fctrl is gradually reduced by adding the predetermined value A.

  Specifically, the driving force correction amount Fctrl (n−1) in step S105 is a correction amount for reducing the required driving force, and the predetermined value A is the absolute value of the driving force correction amount Fctrl (n−1). It is a predetermined value that decreases. In other words, the predetermined value A is a value that reduces the reduction amount (relaxes the suppression amount) with respect to the required driving force that is reduced by the driving force correction amount in the turning control. That is, when the driving force correction amount and the predetermined value A include a positive / negative concept, the positive value predetermined value A is added to the negative driving amount correction amount Fctrl (n−1). The driving force correction amount in the current turning control can be expressed as [Fctrl = Fctrl (n−1) + A]. In the sense of decreasing the absolute value of the driving force correction amount Fctrl (n−1), the driving force correction amount in the current turning control is [| Fctrl | = | Fctrl (n−1) | − | A |]. The driving force correction amount Fctrl in step S107 can be expressed by subtracting the absolute value of the predetermined value A from the absolute value of the driving force correction amount in step S105.

In step S107, gradually decreasing the absolute value of the driving force correction amount by turning control means that the absolute value of the driving force correction amount Fctrl = Fctrl (n−1) is not zero at a stretch. In other words, the control for preventing the driving force correction amount in the turning control from becoming zero at once is a feature of the processing in step S107. Further, gradually decreasing means, for example, that the processing flow illustrated in FIG. 1 is a routine repetitive process. Therefore, when the predetermined value A is constant, the driving force correction amount calculated in step S107 is gradually increased. Will be reduced. Further, making the driving force correction amount toward zero is not limited to strictly causing the absolute value of the driving force correction amount in turning control to be zero, but reducing the absolute value to be an approximate value of zero. It may mean that. That is, processing is performed to reduce the absolute value of the driving force correction amount in the turning control until it becomes smaller than the predetermined threshold value.

  The driving force correction amount [Fctrl = Fctrl (n−1) + A] calculated in step S107 is output as a correction amount to be output in the current turning control (step S109), and the current driving force control process is terminated. Then, the process returns to the routine repetition process.

  Next, with reference to FIG. 2, the temporal change (rate of change) of the correction of the driving force in the turning state by the driving force control by the driving force control device of this embodiment will be described. According to the time chart illustrated in FIG. 2, a steering angle is generated by steering (time t1), and turning control is executed accordingly. Further, the skid prevention device is activated (time t2), and the skid prevention control is executed. Note that the vehicle before time t1 travels straight in a state where the required driving force increases in response to acceleration / deceleration operations such as an accelerator pedal and the steering angle is zero, and the vehicle is not in a turning state. Turning control and skid prevention control are not executed.

  During the period from time t1 to time t2, the driving force correction amount of the turning control output in step S109 for the turning control is the driving force correction amount Fctrl calculated in step S102. In addition, between the times t1 and t2, the steering angle and the required driving force increase, but the control (correction) of the driving force by the skid prevention device is not executed, so the final command torque during that period is The required driving force is a driving force having a value corrected only by the driving force correction amount Fctrl. That is, in the case illustrated in FIG. 2, a value obtained by subtracting the required driving force by the driving force correction amount Fctrl is the final command torque. In other words, the driving force correction amount Fctrl for turning control is a correction amount for reducing the required driving force between the times t1 and t2, which is the initial state of the turning state.

  Then, in the state where the turning control is being executed, the skid prevention device is operated (time t2), and the skid prevention control is executed. That is, the turning control and the skid prevention control are executed in a superimposed manner. Note that the skid prevention device includes yaw direction rotation (yaw angle), lateral acceleration, lateral jerk, vehicle speed, tire angle (slip angle) detected by various sensors such as the lateral acceleration sensor 5, the steering angle sensor 6, and the yaw rate sensor 7. ), And operates to prevent the frictional force between the tire and the road surface from exceeding the grip limit based on a detection signal such as a steering angle. That is, various sensors monitor the running state of the vehicle, and the detection signal is input to the controller 4. The controller 4 determines whether the vehicle is traveling in the direction intended by the driver and the skid prevention device is activated. Then, the direction of the vehicle is corrected by operating the brake 2 so as to generate a braking force on each wheel 1 or by controlling the output of the driving force source 3.

  Whether or not the skid prevention device has been activated is determined by determining whether or not the skid prevention device is in operation in step S103 of the flowchart described above. In the time chart illustrated in FIG. 2, the driving force correction amount by the turning control when the skid prevention device is activated is a correction amount for reducing the required driving force. Therefore, the driving force correction amount by the turning control is maintained by the operation of the skid prevention device. When the skid prevention device is operating (between t2 and t9), the driving force correction amount Fvsc by the skid prevention device is a correction amount for reducing the required driving force.

  Further, the temporal change (change rate) of the steering angle detected by the steering angle sensor 6 is constant (time t3). That is, the steering angle sensor 6 that detects the steering angle corresponding to the steering by the driver detects that the rate of change of the steering angle is zero, that is, a constant steering angle, from the change in which the steering angle increases until then. In other words, between t1 and t3, the steering angle for traveling in the turning direction increases, and at time t3, the steering angle has a steering angle corresponding to the steering and the temporal change (change rate) of the steering angle is constant. Become. Note that the fact that the change in the steering angle over time is constant or the change rate is zero is not limited to the constant or zero change rate in the sense that the steering angle does not change at all. It may be a case of transition so as to approximate a steering angle that is a value. That is, the steering angle changes within a predetermined angle range. In this description, for the sake of convenience in explaining the illustrated time chart, it is expressed as being constant, but may include the above-described concept. Furthermore, not only the steering angle but also the required driving force, the driving force correction amount in the turning control, the driving force correction amount in the side slip prevention control, and the final command torque are expressed as being constant including the above concept. There is.

  The driving force correction amount Fvsc in the skid prevention device decreases the required driving force immediately after the skid prevention device is activated, that is, from the start of the skid prevention control until the change in the steering angle becomes constant (between t2 and t3). It increases rapidly in the direction. In other words, the absolute value of the driving force correction amount Fvsc, which is a correction amount for reducing the required driving amount, rapidly increases in accordance with the temporal change of the steering angle for traveling in the turning direction.

  Although the time point at which the change in the steering angle becomes constant has been described as time t3, the driving force control device according to the present invention is not limited to this. For example, the driving force control device may rapidly reduce the driving force correction amount Fvsc immediately after the operation of the skid prevention device within a preset minute time width. That is, by setting the minute time width between t2 and t3, it is possible to set a time width for sharply reducing the driving force correction amount Fvsc regardless of the steering angle, and to prevent a side slip of the vehicle. It is also possible to improve the operation responsiveness of the prevention device.

  Next, the temporal change (rate of change) of the required driving force becomes constant (time t4). In the time chart illustrated in FIG. 2, the required driving force continues to increase until time t4 is reached, and in order to prevent a side slip of the vehicle, a correction amount for reducing the required driving force is set to a skid prevention device. Is output as the driving force correction amount Fvsc. When the steering angle is constant and the required driving force is increasing (between t3 and t4), the driving force correction amount Fvsc by the skid prevention device is a correction amount for reducing the driving force, and the correction amount The absolute value of increases. Therefore, between t2 and t4, the drive force correction amount Fvsc for the side slip prevention control that is the correction amount for reducing the required drive force is generated, and the absolute value of the drive force correction amount Fvsc is increased. In other words, the driving force correction amount by the skid prevention control is increased.

  That is, the state in which the absolute value of the driving force correction amount Fvsc increases between t3 and t4 changes more slowly than the state in which the absolute value of the driving force correction amount Fvsc increases between t2 and t3. In other words, the absolute value of the driving force correction amount Fvsc between t2 and t3 increases rapidly compared to the change in the absolute value of the driving force correction amount Fvsc between t3 and t4. On the other hand, the driving force correction amount Fctrl for turning control is controlled so that the value is maintained between t3 and t4.

  At time t4, the temporal changes in the steering angle and the required driving force become constant. Therefore, when the steering angle is constant and the required driving force is constant (after time t4), the driving force correction amount Fvsc by the skid prevention device is a correction amount for reducing the required driving force, and its absolute value is decreased. It will be in a state to let you. In other words, the amount of correction (reduction) of the required driving force by the driving force correction amount Fvsc is reduced. That is, the driving force correction amount Fvsc for preventing the side slip is changed from the control state in which the amount of change until the steering angle and the required driving force become constant (between t2 and t4) from the operation of the side slip prevention device from the time t4. Therefore, the control state shifts to a state in which the amount of change decreases.

  Further, the driving force correction amount Fctrl for turning control shifts from the control state in which the value has been held until time t4 to the control state in which the absolute value decreases. That is, when the temporal changes in the steering angle and the required driving force are constant, the driving force correction amount Fctrl is in a state where the absolute value (change amount) decreases from the state where the value is held. . In other words, when the absolute value (change amount) of the driving force correction amount Fvsc by the skid prevention device is reduced, the driving force correction amount Fctrl is changed from the state where the value is held to the absolute value (change amount). ) Decreases. Therefore, in a control state where the absolute value of the driving force correction amount Fvsc by the skid prevention device is reduced, the absolute value of the driving force correction amount Fctrl for the turning control is also reduced. It should be noted that the absolute value (change amount) of the driving force correction amount Fctrl in the turn control when the absolute value (change amount) of the driving force correction amount Fvsc in the side slip prevention control shifts from the increasing control state to the decreasing state. It can also be said that the control state is shifted to the control state in which the absolute value (change amount) is reduced.

  Further, the driving force correction amount Fctrl, which is a correction amount for reducing the required driving force, is controlled so that the absolute value thereof gradually decreases after time t4. In addition, the decrease control gradually decreases the absolute value of the driving force correction amount Fctrl to zero. At the time of the transition back to zero, the driving force correction amount Fctrl is calculated so that the absolute value is decreased by a certain predetermined value A, and is controlled to gradually return to zero. Further, the decrease control may be such that the decrease is continued until the absolute value of the driving force correction amount Fctrl is zero or smaller than a predetermined value B that approximates zero. Therefore, the driving force correction amount Fctrl reduced so as to be smaller than the predetermined value B only needs to be controlled so as not to become larger than the predetermined value B.

  During the reduction control, the skid prevention device determines the driving force correction amount Fvsc by performing feedback control according to the state of the vehicle based on detection signals detected by various sensors. Therefore, the final command torque changes the driving force in a state that is not different from a state in which there is no turning control.

  As a result of the decrease control described above, the driving force correction amount Fctrl for turning control becomes zero (time t5). Then, the control state for decreasing the absolute value of the driving force correction amount Fctrl is stopped. That is, after time t5, the driving force correction amount in the turning control is zero. Further, when the driving force correction amount Fctrl becomes zero (time t5), the skid prevention device stops the control state for decreasing the absolute value of the driving force correction amount Fvsc (time t5), and the driving force correction amount Fvsc at that time point. It shifts to a control state in which the value is held so as to become (after time t5).

  Further, the skid prevention apparatus shifts to a control state in which the absolute value of the driving force correction amount Fvsc is decreased (time t6), and performs reduction control until the absolute value of the correction amount is reduced to zero (between t6 and t9). Meanwhile, the steering angle is restored from the state in which the steering wheel is turned off (between t7 and t8).

  As described above, according to the driving force control device in the present embodiment having the above-described configuration, when both the turning control and the control for ensuring the stability of the vehicle such as the skid prevention device are operated together, the mutual control is performed. Interference can be prevented. In addition, when the control in the skid prevention device is finished from the state in which the turning control and the skid prevention control are mutually operated, the correction amount of the turning control is zero, and the required driving force and the actual output torque There will be no gap and the driver will not feel uncomfortable. Therefore, it is possible to ensure both vehicle stability and prevention of driver discomfort. In addition, a driving force correction amount can be newly output at the next corner to change the longitudinal acceleration of the vehicle and improve the turning performance.

  Further, as shown in the time chart illustrated in FIG. 4, in the driving force control device that considers only turning control, the final command torque is a value obtained by combining the required driving force and the driving force correction amount of the turning control. For example, in the case of No in step S103 or in the case of a driving force control device that does not include a skid prevention device, interference with turning control by the skid prevention device is not considered.

  On the other hand, FIG. 5 is a time chart showing a control state when the turning control is immediately stopped when the skid prevention device is activated. In this case, the turning control is stopped in order to prevent interference with the turning control due to the operation of the skid prevention device. Accordingly, the driving force correction amount Fctrl that has been held for the target turning state until then is released all at once, and its absolute value becomes zero. For this reason, the final command torque is released from the drive amount correction amount for turning control even though the drive force correction amount for reducing the required drive force to prevent the side slip is output from the skid prevention device. The command torque increases for a moment, degrading the stability of the vehicle. However, according to the driving force control apparatus according to the present invention, the stability of the vehicle when the skid prevention apparatus as described above is operated can be ensured, and the driver can be prevented from feeling uncomfortable.

  Further, FIG. 6 illustrates a time chart when the control is stopped after holding the driving force correction amount of the turning control while the skid prevention device is operating. In this case, even when both the turn control and the side slip prevention control are operated, the drive force correction amount for the turn control is maintained, and the drive force correction amount for the side slip prevention is output according to the output request, thereby stabilizing the vehicle. Sex is ensured. However, when the operation of the skid prevention device is finished, the turning control is finished, and the final command torque is deviated from the required driving force or the torque fluctuation occurs when the vehicle is running straight without steering. There was a risk of feeling uncomfortable. On the other hand, according to the driving force control apparatus of the present invention, it is possible to prevent the deviation of the final command torque with respect to the accelerator required driving force, ensure the stability of the vehicle, and give the driver a sense of incongruity. Can be prevented.

  The vehicle driving force control apparatus according to the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the object of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Wheel, 2 ... Brake, 3 ... Driving force source, 4 ... Controller, 5 ... Lateral acceleration sensor, 6 ... Steering angle sensor, 7 ... Yaw rate sensor

Claims (3)

Turning to correct the anti-skid means that to adjust the longitudinal force of each wheel so suppress skidding of vehicles, the request driving force obtained based on the acceleration and deceleration request the vehicle turns in a stable In a vehicle driving force control device comprising a control means,
When both the driving force correction control by the skid control means and the driving force correction control by the turning control means are executed, and the driving force correction amount by the turning control means is a correction amount for reducing the required driving force. together they are configured to hold the driving force correction amount by the turning control means,
The driving force correction amount, which is the amount by which the driving force is changed by the control of the skid prevention means, is a correction amount that reduces the required driving force, and the absolute value of the driving force correction amount by the skid prevention means is When the vehicle is in a decreasing state, the vehicle driving force control device is configured to gradually decrease the absolute value of the driving force correction amount by the turning control means . The driving force correction amount by the skid prevention means is a correction amount for reducing the required driving force , and
If when the change rate and the required driving force of the rate of change of steering the steering angle is smaller than the predetermined value either or both the rate of change is zero, so as to reduce the absolute value of the driving force correction amount by the anti-skid means The vehicle driving force control device according to claim 1, wherein the vehicle driving force control device is configured. When the driving force correction amount, which is the amount by which the driving force is changed by the control of the skid prevention means, is a correction amount to reduce the required driving force, and the absolute value of the driving force correction amount by the skid prevention means is reduced when in, when gradually decreasing the absolute value of the driving force correction amount by the turning control means, the absolute value of the driving force correction amount by the front Symbol swing control means gradually to become smaller than a predetermined value 2. The vehicle driving force control device according to claim 1, wherein the vehicle driving force control device is configured to be decreased so that the absolute value does not become larger than the predetermined value.

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