JP2006115644A - Motor traction controller of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the motor traction controller of a vehicle in which stability can be ensured while protecting the components at the time of motor traction control. <P>SOLUTION: The motor traction controller of a vehicle comprising at least one motor equipped in a power source for driving wheels, a motor traction control means for detecting drive slip of the driving wheel and recovering grip of the driving wheel through motor torque down control is further provided with a component protection control section operating a first torque down amount for component protection, and a stability control section operating a second torque down amount for stabilizing behavior of vehicle wherein the motor traction control means is a means for selecting the larger one of the first torque down amount operated at the component protection control section and the second torque down amount operated at the stability control section as a control target torque down amount. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a motor traction control device for a vehicle that is applied to a hybrid vehicle, an electric vehicle, and the like and in which at least one motor is installed in a power source that drives a drive wheel.

In hybrid vehicles and electric vehicles equipped with a motor as the power source for driving the drive wheels, when the drive wheels slip, the motor over-rotates in accordance with the drive slip of the drive wheels, and an overcurrent is generated in the motor drive circuit. Therefore, it is necessary to converge the drive slip with good response in order to protect the parts. The motor traction control device for converging the drive slip for the purpose of protecting the components is configured to predict that the drive slip will occur when the change rate (angular acceleration) of the rotational angular velocity of the drive wheel is equal to or greater than a predetermined value, and to reduce the motor torque. And driving slip that occurs with an increase in motor torque is prevented (see, for example, Patent Document 1).
JP-A-10-304514

  However, in the above-described conventional motor traction control device, priority is given to component protection on a low μ road where drive slip is likely to occur, and when the occurrence of drive slip is predicted, a large motor torque down amount is provided. When drive slip occurs, the motor torque becomes excessively large and the drive wheel potential (traction) is not fully used. Therefore, there is a problem in that behavioral stability (= stability) decreases and acceleration (= stumbling) occurs. In particular, a vehicle equipped with a motor as a power source for driving the drive wheels has a quick torque increase / decrease response by the motor, and therefore, such a phenomenon is more likely to occur than an engine vehicle.

  The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a vehicle motor traction control device capable of achieving both protection of parts and ensuring of stability during motor traction control.

In order to achieve the above object, in the motor traction control device for a vehicle according to the present invention, at least one motor provided in a power source for driving the drive wheels and a drive slip of the drive wheels are detected and driven by motor torque down control. In a motor traction control device for a vehicle provided with motor traction control means for recovering the grip of the wheel,
The motor traction control means includes a component protection control unit that calculates a first torque down amount for component protection and a stability control unit that calculates a second torque down amount for stabilizing vehicle behavior. And
The motor traction control means selects the larger torque down amount as the control target torque down amount from the first torque down amount by the component protection control unit and the second torque down amount by the stability control unit. Features.

  Therefore, in the motor traction control device for a vehicle according to the present invention, when a drive slip occurs at the time of starting or during intermediate acceleration, the first torque reduction amount and stability by the component protection control unit in the motor traction control means. Of the second torque reduction amounts by the control unit, the larger torque reduction amount is selected as the control target torque reduction amount. That is, the component protection control unit predicts the occurrence of drive slip and gives a high first torque down amount. However, when the gripping force of the drive wheels is recovered by giving the first torque down amount, the first torque is reversed. The amount of down decreases at a stretch, and the magnitude relationship with the second torque down amount by the stability control unit is reversed in the middle of the decrease in the first torque down amount. Therefore, since the first torque down amount is selected while the relationship of the first torque down amount ≧ the second torque down amount, the component protection control unit causes the overcurrent flowing through the circuit components of the high voltage unit or the motor. Occurrence of excessive rotation of mechanical parts such as a gear to be rotated is suppressed. After that, when the relationship between the two torque-down amounts changes to the relationship of the first torque-down amount <the second torque-down amount, the second torque-down amount is selected, so the stability control unit maximizes the potential of the drive wheels. The drive slip is controlled so that it can be used up. As a result, at the time of motor traction control, it is possible to achieve both protection of parts and ensuring stability.

  Hereinafter, the best mode for realizing a motor traction control device for a vehicle according to the present invention will be described based on Examples 1 to 5 shown in the drawings.

First, the drive system configuration of the hybrid vehicle will be described.
FIG. 1 is an overall system diagram showing a drive system of a hybrid vehicle to which the motor traction control device of Embodiment 1 is applied. As shown in FIG. 1, the drive system of the hybrid vehicle in the first embodiment includes an engine E, a first motor generator MG1, a second motor generator MG2 (motor), an output sprocket OS, and a power split mechanism TM. Have.

  The engine E is a gasoline engine or a diesel engine, and the opening degree of a throttle valve and the like are controlled based on a control command from an engine controller 1 described later.

The first motor generator MG1 and the second motor generator MG2 are synchronous motor generators in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator. Based on a control command from the motor controller 2 described later, Each is controlled independently by applying a three-phase alternating current generated by the control unit 3.
Both of the motor generators MG1 and MG2 can operate as electric motors that are rotated by receiving power supplied from the battery 4 (hereinafter, this state is referred to as “powering”), and the rotor is rotated by an external force. If it is, the battery 4 can be charged by functioning as a generator that generates electromotive force at both ends of the stator coil (hereinafter, this state is referred to as “regeneration”).

  The power split mechanism TM is configured by a simple planetary gear having a sun gear S, a pinion P, a ring gear R, and a pinion carrier PC. And the connection relationship of the input / output member with respect to the three rotating elements (sun gear S, ring gear R, and pinion carrier PC) of the simple planetary gear will be described. A first motor generator MG1 is connected to the sun gear S. A second motor generator MG2 and an output sprocket OS are connected to the ring gear R. An engine E is connected to the pinion carrier PC via an engine damper ED. The output sprocket OS is connected to the left and right front wheels (drive wheels) via a chain belt CB, a differential and a drive shaft (not shown).

Due to the above connection relationship, the first motor generator MG1 (sun gear S), the engine E (planet carrier PC), the second motor generator MG2 and the output sprocket OS (ring gear R) are arranged in this order on the alignment chart shown in FIG. It is possible to introduce a rigid lever model (a relationship in which three rotational speeds are always connected by a straight line) that can simply express the dynamic operation of a simple planetary gear.
Here, the “collinear diagram” is a velocity diagram used in a simple and easy-to-understand method of drawing instead of the method of obtaining by equation when considering the gear ratio of the differential gear, Take the number of rotations (rotation speed) of the rotating elements, take each rotating element on the horizontal axis, and set the interval between each rotating element to the collinear lever ratio (1: λ) based on the gear ratio λ of the sun gear S and ring gear R It arrange | positions so that it may become.

Next, the control system of the hybrid vehicle will be described.
As shown in FIG. 1, the hybrid vehicle control system in the first embodiment includes an engine controller 1, a motor controller 2, a power control unit 3 (high power unit), a battery 4 (secondary battery), and a brake controller 5. And an integrated controller 6.

  The integrated controller 6 receives input information from an accelerator opening sensor 7, a vehicle speed sensor 8, an engine speed sensor 9, a first motor generator speed sensor 10, and a second motor generator speed sensor 11. Brought about. Note that the vehicle speed sensor 8 and the second motor generator rotation speed sensor 11 are for detecting the output rotation speed of the same power split mechanism TM, so the vehicle speed sensor 8 is omitted and the second motor generator rotation speed sensor 11 The sensor signal may be used as a vehicle speed signal.

  The brake controller 5 includes a front left wheel speed sensor 12, a front right wheel speed sensor 13, a rear left wheel speed sensor 14, a rear right wheel speed sensor 15, and a steering angle sensor 16 (steering angle detection means). Input information is provided from the master cylinder pressure sensor 17, the brake stroke sensor 18, the yaw rate sensor 27, and the lateral acceleration sensor 28.

  The engine controller 1 responds to an engine operating point (Ne) according to a target engine torque command or the like from an integrated controller 6 that inputs an accelerator opening AP from an accelerator opening sensor 7 and an engine speed Ne from an engine speed sensor 9. , Te), for example, is output to a throttle valve actuator (not shown).

  The motor controller 2 receives the motor of the first motor generator MG1 in response to a target motor generator torque command or the like from the integrated controller 6 that inputs the motor generator rotational speeds N1 and N2 from the motor generator rotational speed sensors 10 and 11 by the resolver. A command for independently controlling the operating point (N1, T1) and the motor operating point (N2, T2) of the second motor generator MG2 is output to the power control unit 3. The motor controller 2 uses information on the battery S.O.C that indicates the state of charge of the battery 4.

  The power control unit 3 constitutes a high-power unit based on a high-voltage power supply system that can supply power to both motor generators MG1 and MG2 with a smaller current. As shown in FIG. It has a boost converter 3b, a drive motor inverter 3c, a generator generator inverter 3d, and a capacitor 3e. A drive motor inverter 3c is connected to the stator coil of the second motor generator MG2. A generator generator inverter 3d is connected to the stator coil of the first motor generator MG1. The joint box 3a is connected to a battery 4 that is discharged during power running and charged during regeneration.

The brake controller 5 outputs a control command to the brake fluid pressure unit 19 that independently controls the brake fluid pressure of the four wheels so as to prevent the occurrence of braking lock during low μ road braking or sudden braking. “ABS control” is performed. In addition, a VDC that outputs a motor traction control command to the integrated controller 6 and a control command to the brake fluid pressure unit 19 is output so as to ensure vehicle behavior stability at the time of a lane change or emergency avoidance of an obstacle. (VDC is an abbreviation for Vehicle Dynamics Control and may also be called VSC (Vehicle Stability Control System) or the like). Further, during braking by the engine brake or foot brake or during deceleration, the regenerative cooperative control command to the integrated controller 6 and the brake hydraulic pressure unit 19 are obtained so as to obtain the required braking force while collecting braking and deceleration energy. Perform “regenerative cooperative brake control” to issue control commands.
The brake controller 5 includes wheel speed information from the wheel speed sensors 12, 13, 14, 15, steering angle information from the steering angle sensor 16, braking operation from the master cylinder pressure sensor 17 and the brake stroke sensor 18. Quantity information, yaw rate information from the yaw rate sensor 27, and lateral acceleration information from the lateral acceleration sensor 28 are input.
And based on these input information, a predetermined calculation process is performed and the control command by the process result is output to the integrated controller 6 and the brake hydraulic pressure unit 19. A front left wheel wheel cylinder 20, a front right wheel wheel cylinder 21, a rear left wheel wheel cylinder 22, and a rear right wheel wheel cylinder 23 are connected to the brake fluid pressure unit 19.

The integrated controller 6 manages the energy consumption of the entire vehicle and has a function for running the vehicle with the highest efficiency. The integrated controller 6 performs engine operating point control by a control command to the engine controller 1 during acceleration running or the like. In addition, the motor generator operating point control is performed by a control command to the motor controller 2 at the time of stopping, running, braking, or the like.
The integrated controller 6 includes the accelerator opening AP, the vehicle speed VSP, the engine speed Ne, the first motor generator speed N1, and the second motor generator speed N2 from the sensors 7, 8, 9, 10, and 11. Entered.
And based on these input information, a predetermined calculation process is performed and the control command by the process result is output to the engine controller 1 and the motor controller 2. FIG. The integrated controller 6 and the engine controller 1, the integrated controller 6 and the motor controller 2, and the integrated controller 6 and the brake controller 5 are connected by bidirectional communication lines 24, 25, and 26, respectively, for information exchange.

Next, driving force performance will be described.
As shown in FIG. 2 (b), the driving force of the hybrid vehicle of the first embodiment includes the engine direct driving force (the driving force obtained by subtracting the generator driving amount from the total engine driving force) and the motor driving force (both motor generators MG1). , Driving force by the sum of MG2). As shown in FIG. 2A, the maximum driving force is configured such that the lower the vehicle speed, the greater the motor driving force. In this way, since the vehicle does not have a transmission and travels by adding the direct driving force of the engine E and the motor driving force that is electrically converted, the full power of the accelerator pedal is fully opened from low speed to high speed from the state of low steady driving power. Until now, it is possible to control the driving force seamlessly with good response to the driver's required driving force (torque on demand).
In the hybrid vehicle of the first embodiment, the engine E, the motor generators MG1 and MG2, and the left and right front wheels are connected without a clutch via the power split mechanism TM. Further, as described above, most of the engine power is converted into electric energy by a generator, and the vehicle is driven by a motor with high output and high response. For this reason, for example, when driving on slippery roads such as an ice burn, when the driving force of the vehicle changes suddenly due to slipping of driving wheels or locking of driving wheels during braking, the power control unit 3 from excessive current It is necessary to protect the parts from the pinion over rotation of the power split mechanism TM. On the other hand, taking advantage of the characteristics of high-output and high-response motors, it has been developed from a component protection function to detect the drive slip of the drive wheel instantly, recover its grip, and drive the vehicle safely Adopts traction control.

Next, the braking force performance will be described.
In the hybrid vehicle of the first embodiment, the kinetic energy of the vehicle is converted into electric energy by operating the second motor generator MG2 operating as a motor as a generator (generator) during braking by an engine brake or a foot brake. Then, a regenerative braking system that recovers and reuses the battery 4 is adopted.
As shown in Fig. 3 (a), the general regenerative brake cooperative control in this regenerative brake system calculates the required braking force with respect to the brake pedal depression amount, regardless of the magnitude of the required braking force. The required braking force is shared by the regenerative component and the hydraulic component.
In contrast, the regenerative brake cooperative control employed in the hybrid vehicle of the first embodiment calculates the required braking force with respect to the brake pedal depression amount as shown in FIG. 3 (b), and calculates the calculated required braking force. On the other hand, the regenerative brake is given priority, and as long as the regenerative portion can cover it, the regenerative portion is expanded to the maximum without using the hydraulic component. Thereby, especially in a traveling pattern in which acceleration / deceleration is repeated, energy recovery efficiency is high, and energy recovery by regenerative braking is realized up to a lower vehicle speed.

Next, the vehicle mode will be described.
As the vehicle mode in the hybrid vehicle of the first embodiment, as shown in the collinear diagram of FIG. 4, “stop mode”, “start mode”, “engine start mode”, “steady travel mode”, “acceleration mode” Have
In the “stop mode”, as shown in FIG. 4A, the engine E, the generator MG1, and the motor MG2 are stopped. In the “start mode”, as shown in FIG. 4 (2), the vehicle starts by driving only the motor MG2. In the “engine start mode”, as shown in FIG. 4 (3), the sun gear S rotates to start the engine E by the generator MG1 having a function as an engine starter. In the “steady travel mode”, as shown in FIG. 4 (4), the vehicle travels mainly by the engine E, and power generation is minimized in order to increase efficiency. In the “acceleration mode”, as shown in FIG. 4 (5), the engine E is rotated and the generator MG1 starts generating power. The electric power of the battery 4 is used to increase the driving force of the motor MG2. In addition, it accelerates.
In reverse running, in the “steady running mode” shown in FIG. 4 (4), if the rotation speed of the generator MG1 is increased while the increase in the rotation speed of the engine E is suppressed, the rotation speed of the motor MG2 becomes negative. Transition and reverse travel can be achieved.

  At the time of start-up, when the ignition key is turned, the engine E starts, and after the engine E is warmed up, the engine E stops immediately. When starting or at a light load, when starting or when going down a gentle hill that runs at a very low speed, the fuel is cut in areas where engine efficiency is low, and the engine stops and the motor MG2 runs. During normal travel, the driving force of the engine E is driven directly by one of the wheels by the power split mechanism TM, while the other drives the generator MG1 and assists the motor MG2. At the time of full open acceleration, power is supplied from the battery 4 and further driving force is added. When decelerating or braking, the wheel drives the motor MG2 and acts as a generator to perform regenerative power generation. The collected electrical energy is stored in the battery 4. When the charge amount of the battery 4 decreases, the generator MG1 is driven by the engine E and charging is started. When the vehicle is stopped, the engine E is automatically stopped except when the air conditioner is used or when the battery is charged.

Next, the operation will be described.
[Motor traction control process]
FIG. 6 is a flowchart showing the flow of the motor traction control process executed by the integrated controller 6 of the first embodiment. Each step will be described below (motor traction control means).

In step S1, a required motor torque obtained by subtracting the engine shared torque from the required drive torque determined by the accelerator opening, the vehicle speed, etc. is calculated, and the process proceeds to step S2.
It should be noted that when traveling using only the second motor generator MG2 as a drive source, the engine sharing torque is zero, and when traveling using the second motor generator MG2 and the engine E as driving sources, the engine sharing torque is the engine direct driving force. (See FIG. 2).

In step S2, following the calculation of the required motor torque in step S1, the angular acceleration ω ′ of the front wheels (= second motor generator MG2) is calculated based on the sensor signal from the second motor generator rotation speed sensor 11, The process proceeds to S3.
Here, the “angular acceleration ω ′” can be calculated by differentiating the angular velocity (= second motor generator rotational speed) with respect to time. As a differential calculation method, for example, when the sampling time is 10 msec, the differential value is calculated by taking the deviation between the current second motor generator rotation speed measurement value and the second motor generator rotation speed measurement value 10 msec before. be able to.

In step S3, following the calculation of the angular acceleration ω ′ in step S2, the first torque reduction amount is calculated according to the magnitude of the angular acceleration ω ′, and the process proceeds to step S4 (component protection control unit).
Here, for example, as shown in FIG. 7, the calculation of the first torque down amount is performed such that the torque down amount = 0 when the angular acceleration ω ′ is zero to the first set value ω1 ′, and the angular acceleration ω ′ is the first. From the set value ω1 ′ to the second set value ω2 ′, a torque down amount that increases in proportion to the increase in the angular acceleration ω ′ is given, and when the angular acceleration ω ′ exceeds the second set value ω2 ′, a constant maximum torque down is achieved. Give the amount MAX.

In step S4, following the calculation of the first torque down amount in step S3, the first target motor torque TM1 ^{* is} obtained by subtracting the first torque down amount obtained in step S3 from the required motor torque obtained in step S1 ^. And the process proceeds to step S5.

In step S5, following the calculation of the first target motor torque TM1 ^* in step S4, the front wheel slip ratio ρ is calculated based on the wheel speed information from the four wheel speed sensors 12, 13, 14, and 15. The process proceeds to step S6.
Here, the calculation of the “slip ratio ρ” is performed when the average wheel speed of the left and right rear wheels is the vehicle speed Vb, and the average vehicle speed of the left and right front wheels is the drive wheel speed Vw.
ρ = (Vw−Vb) / Vw
It is calculated by the following formula. Instead of the slip ratio ρ, a slip amount obtained by subtracting the vehicle body speed Vb from the driving wheel speed Vw may be used.

In step S6, following the calculation of the slip ratio ρ in step S5, the second torque reduction amount is calculated according to the magnitude of the slip ratio ρ, and the process proceeds to step S7 (stability control unit).
Here, in the calculation of the second torque down amount, for example, as shown in FIG. 8, the torque down amount is given so that the slip rate ρ falls within the TCS control region of around 20%. That is, as the slip ratio ρ increases, both the driving force coefficient μd and the lateral force Fy of the longitudinal force decrease. In particular, the decrease in the lateral force Fy causes the side-sliding frictional force of the drive wheel to be lost, which adversely affects steering stability. The motor traction stability control is a control system that limits the slip ratio ρ to an appropriate range in order to secure driving force and improve acceleration performance while preventing a decrease in running stability.

In step S7, following the calculation of the second torque down amount in step S6, the second target motor torque TM2 ^{* is} obtained by subtracting the second torque down amount obtained in step S6 from the required motor torque obtained in step S1 ^. And the process proceeds to step S8.

In step S8, following the calculation of the second target motor torque TM2 ^* in step S7, the first target motor torque TM1 ^* obtained in step S4 and the second target motor torque TM2 ^* obtained in step S7 are calculated. The motor torque command value is selected by select low, and the process proceeds to step S9.
That is, the selection of the motor torque command value that is the control target by the select low of the first target motor torque TM1 ^* and the second target motor torque TM2 ^* means that the first torque down amount in step S3 and the second torque in step S6. This is synonymous with selecting the larger torque down amount as the control target torque down amount among the two torque down amounts.

In step S9, following the selection of the motor torque command value in step S8, the selected motor torque command value is output to the motor controller 2, and the process proceeds to return.
[Background of traction control]
Including JP-A-6-229264, JP-A-5-312061, etc., when a drive slip occurs in a drive wheel, torque reduction control is performed to adjust the drive torque applied to the drive wheel according to the drive slip state. A number of vehicle traction control devices to be implemented have been announced.

When the vehicle traction control device adopts a system for controlling the driving torque of the engine, the following points may be problematic when the vehicle is traveling at a low speed, particularly when starting.
In order to keep the driving slip generated when the driver performs excessive accelerator operation at the time of starting, it is desirable to start the traction control as early as possible. It is necessary to detect the driving slip as early as possible by setting a low value to the following). Especially at low vehicle speeds, the operation delay time of the engine, transmission, etc. is large, so detection of early driving slip is necessary. Is effective in suppressing driving slip.
However, if the slip reference value is set low at low vehicle speeds, the driving torque will be reduced too much, and in some cases the engine speed will be extremely low and engine vibration will increase, resulting in poor driving feeling. If the engine speed is too low, the engine may stall (is stalled). As a result, the slip reference value at the initial stage of slip needs to be set to a high value.

  However, if the slip reference value at the initial stage of the slip is set to a high value, under steering on an icy road, under steering occurs in the FF vehicle, over steering occurs in the FR vehicle, and the secondary battery and When this control is used in an electric vehicle using a drive motor, etc., power generation by the generator cannot catch up, resulting in an increase in the amount of power taken from the secondary battery, resulting in a large current. May occur.

In order to solve the above problems, Japanese Patent Laid-Open Nos. 60-104428 and 62-265430 have been proposed, and these include slip reference values when the vehicle speed (vehicle speed) is low. A technique is disclosed in which the slip determination level is changed so as to allow more drive slips (a determination direction in which slipping occurs more).
Further, as described in JP-A-5-312061, after the start of drive torque adjustment by the drive torque adjustment means, the slip reference value is changed to a value higher than the initially set value, thereby improving driving feeling and engine stall. A technique for preventing the above is disclosed. However, in these prior arts, power and current are not considered.

  On the other hand, Japanese Patent Laid-Open No. 10-304514 discloses a technique (angular acceleration control) for improving responsiveness in the initial stage of slip, not the slip ratio. This technique is often applied to a vehicle using a motor as a unit for generating a driving force, such as a hybrid vehicle, an electric vehicle, and a fuel cell vehicle.

  As shown in FIG. 9, this technology has an angular acceleration calculation unit, a driving force limit calculation unit, and a torque limit calculation unit, and the rate of change (angular acceleration) of the rotational angular velocity of the drive wheels is a predetermined value or more. In some cases, driving slip is predicted to occur, and the motor torque is reduced (limited). With this configuration, it is possible to prevent a drive slip that occurs with an increase in motor torque.

Here, the reason why “angular acceleration control” that suppresses slip with high responsiveness in the early stage of generation of drive slip in a hybrid vehicle using a motor as a unit for generating drive force will be described.
If there is no motor traction control device and the drive slips, the power generation of the engine cannot catch up and the motor draws more current from the battery. Therefore, an overcurrent is generated in the motor drive circuit, and the elements on the circuit are damaged. For example, in the power control unit 3 according to the first embodiment, as shown by the arrow in FIG. 5, when an overcurrent flows through the capacitor 3e, the fuse of the joint box 3a and the switching circuit of the boost converter 3b are damaged. There is a case. Moreover, in a hybrid vehicle or a fuel cell vehicle, overcurrent tends to flow as the motor output (motor output ratio) is larger than that of the secondary battery. In addition, overvoltage and overcurrent flow more easily as the output of the engine and fuel cell (engine output ratio) is larger than that of the secondary battery. There is a relationship.
Therefore, in order to reliably protect the parts, it is necessary to perform motor traction control that converges the drive slip with good response by "angular acceleration control" in which torque is limited when slipping.

  However, in the conventional “angular acceleration control”, priority is given to component protection on a low μ road where drive slip is likely to occur, and a large motor torque down amount is provided when the occurrence of drive slip is predicted. For this reason, for example, as shown in FIG. 10 (a), when the driving wheel speed increases due to the occurrence of driving slip, the motor torque decreases, and the driving wheel speed also decreases as the motor torque decreases. This reduction in the driving wheel wheel speed exceeds the optimum slip amount range (optimum slip ratio range) and falls to the vehicle body speed level. When the driving wheel speed decreases to the vehicle body speed level, the motor torque is allowed to increase, and the driving wheel speed becomes a re-slip situation where the driving wheel speed increases again. Repeated.

  That is, in the case of “angular acceleration control”, the occurrence of overcurrent can be prevented by detecting slip start at an early stage and entering torque down control, but as shown in FIG. 10B, the optimum slip amount with high cornering power is obtained. In contrast to the range, the actual control range is expanded to a region where the slip amount (slip rate) is low and is also expanded to a high region, so that the potential of the drive wheels is not fully used.

  Therefore, in the case of “angular acceleration control”, as shown in FIG. 11, when the output decrease of the driving torque is too large and the driving wheel speed sticks to the vehicle speed (vehicle speed), the acceleration failure (stumble) due to rattling There is a problem that occurs.

  In the case of “angular acceleration control”, as shown in FIG. 10 and FIG. 11, if the generation of slip (slip amount is large) and slip convergence (slip amount is small) are repeated in the drive wheel, There is a problem that front-rear G hunting occurs in which the front-rear G of the vehicle fluctuates due to the reaction force.

  On the other hand, Japanese Patent Laid-Open No. 2001-295676 discloses a hunting prevention technology that repeats the generation and stoppage of slip by changing the relaxation condition of the torque limit. Remains to the fullest extent, leaving the problem of reduced stability and traction performance.

[Motor traction control function]
In contrast to the above-described background art, in the motor traction control device for a hybrid vehicle according to the first embodiment, as the motor traction control, “angular acceleration control” for calculating a first torque down amount for component protection and for stabilizing the vehicle behavior. And the “slip rate control” for calculating the second torque down amount of the first torque down amount by the “angular acceleration control” and the second torque down amount by the “slip rate control”. By selecting the larger torque as the control target torque reduction amount, both the protection of parts and the securing of stability are achieved at the time of motor traction control.

That is, when a driving slip occurs, the flow proceeds from step S1 to step S2 to step S3 to step S4 in the flowchart of FIG. 6, and in step S3, according to the magnitude of the angular acceleration ω ′ of the front wheel that is the driving wheel. In step S4, the first target motor torque TM1 ^* is calculated by subtracting the first torque reduction amount from the required motor torque.

Then, the flow proceeds from step S4 to step S5 → step S6 → step S7. In step S6, the second torque-down amount is calculated according to the magnitude of the slip ratio ρ of the front wheels that are drive wheels, and step S7. , The second target motor torque TM2 ^* is calculated by subtracting the second torque reduction amount from the required motor torque.

Further, the flow proceeds from step S7 to step S8 to step S9. In step S8, a motor torque command value is selected by a select low of the first target motor torque TM1 ^* and the second target motor torque TM2 ^*, and step S9. The torque command for obtaining the selected motor torque command value is output.

  Accordingly, the motor traction control operation will be described with reference to FIG. 12, taking as an example the case where a drive slip occurs at the time of starting. If drive slip occurs immediately after starting, it is predicted that the slip ratio (slip amount) will become excessive due to the large angular acceleration ω ′ of the drive wheel, and a high first torque reduction amount by “angular acceleration control” is predicted. The giving command is output. When the gripping force of the driving wheel is restored by giving this high first torque reduction amount, the angular acceleration of the driving wheel decreases, and the driving wheel speed characteristic also changes from a state where the angular acceleration is zero to a state where the angular acceleration is negative. By shifting and the drive slip converging, a command for reducing the first torque reduction amount by “angular acceleration control” at a stretch is output. That is, in the middle of the decrease in the first torque reduction amount, the magnitude relationship with the second torque reduction amount by the “slip rate control” is reversed.

  Therefore, during the period from time t0 to time t1 in FIG. 12 (a) in which the first torque down amount ≧ the second torque down amount, “angular acceleration control” for calculating the first torque down amount is selected. Therefore, the occurrence of overcurrent flowing through the circuit parts of the power control unit 3 and over-rotation of mechanical parts such as the pinion P rotated by the second motor generator MG2 by executing “angular acceleration control” which is the part protection control. Is suppressed.

  Then, after the time t1, when the relationship between the two torque-down amounts changes to the relationship of the first torque-down amount <the second torque-down amount, the mode is switched to “slip rate control” for selecting the second torque-down amount. As shown in (a), in the “slip rate control”, a control is performed to keep the wheel speed fluctuation range of the drive wheels small. With this “slip rate control”, as shown in FIG. 12B, the slip rate (slip amount) falls within a region where the cornering power of the drive wheels is high. In other words, the drive slip is controlled so that the potential of the drive wheel is fully used. Note that when switching from “angular acceleration control” to “slip rate control”, as is apparent from the wheel speed characteristics of the drive wheels after time t1 in FIG. Since there is no large angular acceleration that exceeds the angular acceleration threshold in "Angular acceleration control", "Angular acceleration control" does not intervene in the middle of "Slip rate control". "Control" is maintained.

  As described above, in the motor traction control device according to the first embodiment, during the motor traction control, the torque down amount among the first torque down amount by the “angular acceleration control” and the second torque down amount by the “slip rate control”. Since the control with which the larger value is selected as the control target torque reduction amount is selected, in FIG. 10 (a) and FIG. 12 (a), the acceleration of the vehicle body may be improved in FIG. 12 (a). As can be seen, it is possible to reliably protect the parts and to secure the traction performance associated with the stability.

  Further, in the “slip rate control”, as described above, since the slip rate (slip amount) of only the region where the driving wheel cornering power is high is used and the wheel speed fluctuation of the drive wheel is suppressed, the vehicle longitudinal G is The occurrence of fluctuating front and rear G hunting can also be suppressed.

Next, the effect will be described.
In the vehicle motor traction control device of the first embodiment, the effects listed below can be obtained.

  (1) Provided with at least one motor provided in a power source for driving the driving wheel, and motor traction control means for detecting driving slip of the driving wheel and recovering the grip of the driving wheel by motor torque down control. In the motor traction control device for a vehicle, the motor traction control means calculates a component protection control unit for calculating a first torque down amount for component protection and a second torque down amount for stabilizing the vehicle behavior. A stability control unit, wherein the motor traction control means has a larger torque down amount between a first torque down amount by the component protection control unit and a second torque down amount by the stability control unit. Since it is selected as the control target torque reduction amount, it is necessary to ensure component protection and stability during motor traction control. Can be achieved.

  (2) The component protection control unit is an angular acceleration control unit that detects a driving slip based on an angular acceleration of a driving wheel to which the motor is connected, and performs motor torque down control when the angular acceleration exceeds a set threshold value. By predicting an excessive driving slip due to the occurrence of angular acceleration exceeding the set threshold, and suppressing the over-rotation of the motor with good response, it is possible to effectively achieve protection of parts of the power control unit 3 and the power split mechanism TM. it can.

  (3) The stability control unit detects a drive slip based on a slip ratio of a drive wheel to which the motor is connected, and performs motor torque down control so that the slip ratio falls within an appropriate range for securing a road surface grip of the drive wheel. Since it is a slip ratio control unit that performs, when slip ratio control is entered, control is performed using only the slip ratio (slip amount) of the region where the driving wheel cornering power is high, traction performance can be ensured, and the vehicle front-rear G is The occurrence of fluctuating front and rear G hunting can also be suppressed.

  The second embodiment is an example in which, when the second torque reduction amount is calculated in the stability control unit, a larger phase delay is given such that the estimated road surface friction coefficient indicates a lower friction coefficient.

  That is, in the “slip rate control” of the first embodiment, as shown in FIG. 13A, when the configuration for calculating the second torque reduction amount is the driving force limit calculating unit 30, the driving force limit calculating The unit 30 includes a second torque-down amount calculation unit 30a that calculates a second torque-down amount according to the slip ratio ρ, and the road surface μ is low μ as the second torque-down amount from the second torque-down amount calculation unit 30a. And a second torque down amount command value calculation unit 30b that gives a larger phase delay.

  The second torque-down amount output value calculation unit 30b calculates a command value for the second torque-down amount using a 1 / (TS + 1) first-order phase lag equation, and its time constant T is shown in FIG. As shown in the T-μ table of b), the highest value is given when the estimated road surface μ is low μ, and is given by a proportionally lower value as the estimated road surface μ becomes higher.

  Here, the estimation of the road surface μ is, for example, estimated that the smaller the second torque down amount calculated by the second torque down amount calculating unit 30a is, the lower the road surface μ is (corresponding to the road surface friction coefficient). Value estimation means). In addition, since the structure of other Example 2 is the same as that of Example 1, illustration and description are abbreviate | omitted.

  Explaining the action, for example, when starting on a low μ road or during intermediate acceleration, there is a possibility of slip-up even with a minute torque fluctuation. On the other hand, when the second torque down amount calculated from the slip ratio (slip amount) for maintaining the traction is small (= when the road surface μ is small), as shown in FIG. 13 (c), the road surface μ is low μ. The longer the phase delay time of the torque command value is, the smaller the torque change amount is, as shown in FIGS. 13 (d) and 13 (e).

  Therefore, when starting or during intermediate acceleration, on high μ roads that do not slip up due to minute torque fluctuations, the “slip rate ρ has improved convergence to the optimum range by the second torque down amount with good response. Rate control "can be performed. Further, on a low μ road that slips up due to minute torque fluctuations, it is possible to execute “slip rate control” with high stability by suppressing the amount of torque change to prevent slip-up. Since other operations are the same as those in the first embodiment, description thereof is omitted.

Next, the effect will be described.
In the vehicle motor traction control device of the second embodiment, in addition to the effects (1), (2), (3) of the first embodiment, the following effects can be obtained.

  (4) Road surface friction coefficient equivalent value estimation means for estimating the road surface friction coefficient equivalent value is provided, and in the “slip ratio control”, when the second torque reduction amount is calculated, the estimated road surface friction coefficient equivalent value is low friction. Since the phase delay increases as the coefficient is shown, when executing the “slip ratio control”, when the road surface μ is high μ, the convergence of the slip ratio ρ to the optimum range can be improved. In the case of a low μ, stability by preventing slip-up can be improved.

  In the third embodiment, when the second torque reduction amount is calculated in the stability control unit, the estimated road surface friction coefficient gives a large phase delay as the low friction coefficient is shown, and in the extremely low friction coefficient region of a predetermined value or less. This is an example in which a phase delay upper limit value is set.

  That is, in the “slip rate control” in the first embodiment, as shown in FIG. 14A, when the configuration for calculating the second torque reduction amount is the driving force limit calculating unit 30, the driving force limit calculating is performed. The unit 30 includes a second torque-down amount calculation unit 30a that calculates a second torque-down amount according to the slip ratio ρ, and the road surface μ is low μ as the second torque-down amount from the second torque-down amount calculation unit 30a. And a second torque down amount command value calculation unit 30b ′ that gives a phase delay upper limit value in a region where the estimated road surface μ is equal to or less than a predetermined value.

  The second torque-down amount output value calculation unit 30b ′ calculates a command value for the second torque-down amount using a 1 / (TS + 1) first-order phase lag equation, and its time constant T is shown in FIG. As shown in the T-μ table in (b), in the region where the estimated road surface μ is less than or equal to the predetermined value (= μ1: road surface μ equivalent to an icing road), the time constant T is set to a constant value t to set the upper limit of phase delay. In an area where the estimated road surface μ is equal to or greater than the predetermined value μ1, the higher the estimated road surface μ, the lower the value.

  Here, the estimation of the road surface μ is, for example, estimated that the smaller the second torque down amount calculated by the second torque down amount calculating unit 30a is, the lower the road surface μ is (corresponding to the road surface friction coefficient). Value estimation means). In addition, since the structure of other Example 3 is the same as that of Example 1, illustration and description are abbreviate | omitted.

  Explaining the action, for example, if the phase is made too slow when the road surface μ is extremely low, the response to the road surface change becomes slow, and an acceleration failure occurs. On the other hand, in the third embodiment, when the estimated road surface μ is extremely low, the torque rise time can be prevented from being delayed as shown in FIG.

  Therefore, when starting or during intermediate acceleration, on high μ roads that do not slip up due to minute torque fluctuations, the “slip rate ρ has improved convergence to the optimum range by the second torque down amount with good response. Rate control "can be performed. Further, on a low μ road that slips up due to minute torque fluctuations, it is possible to execute “slip rate control” with high stability by suppressing the amount of torque change to prevent slip-up. In addition to these effects of the second embodiment, the third embodiment can improve acceleration failure in a region where the road surface μ is extremely low. Since other operations are the same as those in the first embodiment, description thereof is omitted.

Next, the effect will be described.
In the vehicle motor traction control device of the third embodiment, in addition to the effects of (1), (2), (3) of the first embodiment and (4) of the second embodiment, the following effects can be obtained. it can.

  (5) In the “slip ratio control”, when the second torque reduction amount is calculated, if it is estimated that the estimated road surface friction coefficient equivalent value is an extremely low friction coefficient region having a predetermined value or less, the phase delay upper limit is set. Since the value is set, the acceleration failure can be improved in an extremely low friction coefficient region equivalent to or below an icing road.

  In the fourth embodiment, even when the parts protection control is prioritized over the stability control (the TCS control in the VDC system or the like), the priority order is ignored when the torque control has a larger torque down amount. This is an example in which stability control is selected. Since the configuration is the same as that of the first embodiment, illustration and description are omitted.

Next, the operation will be described.
[Motor traction control process]
FIG. 15 is a flowchart showing the flow of motor traction control processing executed by the brake controller 5 and the integrated controller 6 of the fourth embodiment. Each step will be described below (motor traction control means).

  In step S41, the wheel speed, yaw rate and lateral acceleration are calculated according to the signals input from the wheel speed sensors 12, 13, 14, 15 and the yaw rate sensor 27 and lateral acceleration sensor 28, and the process proceeds to step S42.

  In step S42, following the calculation of the necessary information in step S41, a second torque reduction amount (TCS control amount in the VDC system and other control systems) in “slip rate control” is calculated, and the process proceeds to step S43.

  In step S43, following the calculation of the second torque-down amount in step S42, the first torque-down amount (high-power unit component protection control amount) in “angular acceleration control” is calculated as in step S3 of FIG. The process proceeds to step S44.

In step S44, following the calculation of the first torque reduction amount in step S43, it is determined whether or not the component protection priority flag is set. If the component protection priority flag is set, the process proceeds to step S48. If the component protection priority flag is not set, the process proceeds to step S45.
Here, the “component protection priority flag” is a flag that is set when component protection is deemed necessary. For example, when the angular acceleration of the drive wheels is equal to or greater than a predetermined value, the output power is predetermined in a certain vehicle state. In the case where there is a possibility that an overcurrent flows because the power is higher than the power, the component protection priority flag is set (priority selection means).

  In step S45, following the determination that the component protection priority flag is not set in step S44, it is determined whether there is a torque down request from the VDC system or other control system, and there is a torque down request. If so, the process proceeds to step S46, and if there is no torque down request, the process proceeds to step S47.

  In step S46, following the determination that there is a torque-down request from another control system in step S45, the second torque-down amount calculated in step S42 is selected, and a control command for obtaining the second torque-down amount is output. And move to return.

  In step S47, following the determination that there is no torque-down request from another control system in step S45, a control command without torque-down is output, and the process proceeds to return.

  In step S48, following the determination that the component protection priority flag is set in step S44, it is determined whether or not the first torque down amount by the component protection control is greater than or equal to the second torque down amount by the stability control. If the first torque down amount ≧ the second torque down amount, the process proceeds to step S49. If the first torque down amount <the second torque down amount, the process proceeds to step S50.

  In step S49, following the determination that the first torque down amount ≧ the second torque down amount in step S48, the first torque down amount by the component protection control is selected, and a control command for obtaining the first torque down amount is output. Move to return.

  In step S50, following the determination that the first torque down amount <the second torque down amount in step S48, the component protection priority flag is cleared, and the process proceeds to step S51.

  In step S51, following the clearing of the component protection priority flag in step S50, a second torque down amount by stability control is selected, a control command for obtaining the second torque down amount is output, and the process proceeds to return.

[Parts protection control]
For example, when the driving force (traction) suddenly changes due to driving wheel slip or driving wheel lock when starting or running on a low μ road such as a snowy road or an ice burn, the component protection control is a highly accurate rotation sensor ( The resolver shown in FIG. 16 instantaneously detects the rotation state of the drive shaft and sends a signal to the integrated controller 6, and then the integrated controller 6 controls to reduce the driving force of the second motor generator MG 2 by a command to the motor controller 2. Is done. That is, traction control is performed in which the grip of the driving wheel is recovered and the driving force corresponding to the driver's accelerator operation is transmitted to the road surface. At the same time, if the angular acceleration calculated by the motor controller 2 based on the signal from the resolver is large, the motor torque is limited to prevent sudden current fluctuations and sudden increase in gear rotation of the power split mechanism TM. Serves protective functions.

  As shown in FIG. 16, the “resolver” includes three coils built in the stator, and the output coils B and C are arranged so as to be electrically shifted by 90 °. The rotor has an elliptical shape, and when the rotor rotates, the gap length between the stator and the rotor changes. By passing an alternating current through the coil A, the coils B and C generate an output corresponding to the rotor position, and the sensor can detect the absolute position from the difference between the outputs. Further, the sensor is also used as a rotation sensor by calculating the amount of change in position within a predetermined time by the CPU.

[About VDC system]
The VDC system is a system that ensures stability in the turning direction of the vehicle. Normally, the vehicle turns stably according to the steering operation, but depending on an unexpected situation such as an emergency turn or an external factor, the vehicle tends to have a strong rear wheel skid or a front wheel skid. In such a case, the VDC system automatically performs engine / motor output control and brake control of each wheel to ensure stability, and performs control to alleviate strong front wheel skidding and front wheel skidding. This system senses the state of the vehicle based on signals from various sensors such as the yaw rate sensor 27 and the lateral acceleration sensor 28, and outputs a control signal to the hydro unit 19 that is a brake actuator. It comprises engine / motor output torque control by outputting a control signal to the controller 1 and the motor controller 2.
For example, the following two examples are given as situations where the drive wheel exceeds the lateral grip limit.
(1) The rear wheel is losing grip relative to the front wheel (strong rear wheel skidding).
(2) The front wheel is losing grip relative to the rear wheel (strong front-slip condition).

  The VDC system operates in the situation shown in FIG. 17 and alleviates the strong rear-wheel or front-wheel skidding tendency of the vehicle. The state of the vehicle is determined by detecting the steering angle, the vehicle speed, the yaw rate of the vehicle, and the lateral acceleration of the vehicle, and is calculated by the brake controller 5. Judgment of the strong rear wheel skid tendency of the vehicle is made based on the values of the slip angle of the vehicle body and the slip angular velocity of the vehicle body. When the slip angle of the vehicle body is large and the slip angular velocity is also large, it is calculated that the vehicle body has a strong rear wheel skid tendency (see FIG. 18 (a)). Judgment of a strong front wheel skid tendency of the vehicle is made based on the target yaw rate and the actual yaw rate value of the vehicle. This means that when the driver steers, the vehicle body will not bend if the actual vehicle yaw rate (detected by the yaw rate sensor) is less than the target yaw rate that should be generated (determined from the steering angle and vehicle speed). Therefore, it is calculated that the front wheel skid tendency is large (see FIG. 18B).

  As a method of operating the VDC, for example, when it is determined by the brake controller 5 that the rear wheel side slip or the front wheel side slip tendency is strong, the engine / motor output is reduced and the braking force of the front wheel or rear wheel is determined. And control the yawing moment of the vehicle to alleviate the side slip condition of the vehicle. In other words, in order to mitigate the strong rear-wheel skid tendency of the vehicle, when it is determined that the rear-wheel skid tendency is large, the front wheels or the front and rear wheels outside the turn are braked according to the degree of the tendency, and the vehicle An outward moment is generated to suppress the tendency of skidding on the rear wheels. Further, a decrease in vehicle speed due to the braking force also contributes to ensuring vehicle stability (see FIG. 18 (c)). In order to mitigate the strong front-wheel side slip tendency of the vehicle, when it is determined that the front-wheel side slip tendency is large, the engine / motor output is controlled according to the degree of the tendency, and the front and rear wheels are braked to apply the lateral force. By reducing the front wheel skid tendency (see FIG. 18 (d)).

[Motor traction control function]
Conventionally, as the component protection control, for example, “angular acceleration control” is described in Japanese Patent Laid-Open No. 10-304514, and the VDC system is well known as being mounted on an actual vehicle. Therefore, for example, the component protection priority flag is set because the angular acceleration of the drive wheel is equal to or greater than a predetermined value and component protection is required. As shown in FIG. When the motor torque down control in the VDC system has intervened during the execution, the component protection priority flag from time t1 to time t3 in FIG. Since “control” has priority, the first torque-down amount is selected. Therefore, when the component protection priority flag is reset at time t3 when the first torque down amount becomes zero, at that moment, the second torque down amount is switched to the VDC system, as shown in FIG. 19 (c). The torque down amount varies from zero to the second torque down amount. Therefore, when switching from “angular acceleration control” to “stability control” in the VDC system according to the priority order, drastic torque fluctuations and non-linear torques are generated at the time of switching, so that drivability performance is impaired. There is a problem of adversely affecting the behavior (for example, front and rear G fluctuation).

  On the other hand, in the vehicle motor traction control device of the fourth embodiment, when the component protection control unit is preferentially selected, the second torque reduction amount by the stability control unit is the first by the component protection control unit. If the torque reduction amount is larger than the torque reduction amount, the priority order is ignored and the second torque reduction amount is selected by the stability control unit, so that both protection of parts and stability can be ensured. It is possible to realize a seamless torque change and to stabilize the vehicle behavior.

  That is, when the component protection priority flag is being set and the first torque down amount by the component protection control unit is equal to or larger than the second torque down amount by the stability control unit, step S41 → The process proceeds from step S42 → step S43 → step S44 → step S48 → step S49, and the first torque reduction amount by the component protection control unit is selected.

  When the component protection priority flag is being set and the first torque down amount by the component protection control unit is less than the second torque down amount by the stability control unit, the process proceeds from step S48 to step S450 to step S51. The second torque down amount by the stability control unit of the VDC system is selected.

  Accordingly, as shown in FIG. 19 (d), the first torque reduction is performed from time t1 to time t2 when the component protection priority flag is being set and the relationship of the first torque down amount ≧ the second torque down amount is maintained. The amount of torque is selected and the second torque down amount is selected from the time t2 to the time t3 when the relationship is changed to the relationship of the first torque down amount <the second torque down amount. Therefore, at the time of switching (time t2), a seamless torque change in which sudden torque fluctuations and nonlinear torque are suppressed is achieved, and the vehicle behavior can be stabilized.

Next, the effect will be described.
In the vehicle motor traction control device of the fourth embodiment, in addition to the effects (1), (2), and (3) of the first embodiment, the following effects can be obtained.

  (6) The motor traction control means is provided with priority selection means for preferentially selecting one of the component protection control section and the stability control section, and the motor traction control means protects the parts by the priority selection means. When the control unit is preferentially selected, if the second torque down amount by the stability control unit is larger than the first torque down amount by the component protection control unit, the priority order is ignored and the stability is ignored. Since the second torque down amount is selected by the control unit, when switching from component protection control to stability control, a sudden torque fluctuation or a non-linear torque is suppressed and a seamless torque change is achieved, thereby stabilizing the vehicle behavior. it can.

  In the fifth embodiment, as in the fourth embodiment, when the amount of torque reduction is larger in the stability control, the priority is ignored and the stability control is selected, and the switching between the component protection control and the stability control is performed. This is an example of a more seamless torque change in the region. Since the configuration is the same as that of the first embodiment, illustration and description are omitted.

Next, the operation will be described.
[Motor traction control process]
FIG. 20 is a flowchart showing the flow of the motor traction control process executed by the brake controller 5 and the integrated controller 6 of the fifth embodiment. Each step will be described below (motor traction control means). In addition, since each step of step S61-step S71 performs the same process as each step of step S41-step S51 of FIG. 15, description is abbreviate | omitted.

  In step S72, following the determination that the first torque down amount ≧ the second torque down amount in step S68, the first torque down amount by the component protection control unit tends to decrease, and the second torque down by the stability control unit. It is determined whether or not the amount is increasing. If Yes, the process proceeds to step S73. If No, the process proceeds to step S69.

  In step S73, following the determination that the first torque down amount tends to decrease and the second torque down amount tends to increase in step S72, the component protection priority flag is cleared, and the process proceeds to step S74.

In step S74, following the clearing of the component protection priority flag in step S73, the torque-down amount when the condition is satisfied is held, or the torque-down amount when the condition is satisfied is changed with a gentle gradient.
Here, when changing the torque-down amount when the condition is satisfied with a gentle gradient, the change speed of the torque-down amount is decreased as the steering angle is increased.

  In step S75, following the determination that the first torque down amount <the second torque down amount in step S68, the first torque down amount by the component protection control unit tends to increase, and the second torque down by the stability control unit. It is determined whether or not the amount is decreasing. If Yes, the process proceeds to step S70, and if No, the process proceeds to step S71.

In step S76, following the clearing of the component protection priority flag in step S70, the torque-down amount when the condition is satisfied is held, or the torque-down amount when the condition is satisfied is changed with a gentle gradient.
Here, when changing the torque-down amount when the condition is satisfied with a gentle gradient, as in the case of step S74, the change speed of the torque-down amount is reduced as the steering angle increases.

[Motor traction control function]
The operation when the stability protection in the VDC system intervenes when the component protection priority flag is being set and the component protection control is being executed will be described with reference to FIG.

  First, from time t0 to time t1 in FIG. 21, since the first torque down amount ≧ the second torque down amount, the first torque down amount tends to increase, and the second torque down amount tends to increase. In the flowchart of FIG. 20, the process proceeds from step S61 → step S62 → step S63 → step S64 → step S68 → step S72 → step S69. In step S69, the first torque reduction amount is selected.

  From time t1 to time t2 in FIG. 21, since the first torque down amount ≧ the second torque down amount, the first torque down amount tends to decrease and the second torque down amount tends to increase. In the flowchart of step S61 → step S62 → step S63 → step S64 → step S68 → step S72 → step S73 → step S74, and in step S74, the first torque reduction amount when the condition is satisfied is maintained. Alternatively, the first torque reduction amount when the condition is satisfied is decreased and changed with a gentle gradient.

  From time t2 to time t3 in FIG. 21, since the first torque down amount is smaller than the second torque down amount, the first torque down amount tends to decrease and the second torque down amount tends to increase. In this flowchart, the process proceeds from step S61 → step S62 → step S63 → step S64 → step S68 → step S75 → step S71. In step S71, the second torque reduction amount is selected.

  From time t3 to time t4 in FIG. 21, since the first torque down amount is smaller than the second torque down amount, the first torque down amount tends to decrease and the second torque down amount tends to decrease. In this flowchart, the process proceeds from step S61 → step S62 → step S63 → step S64 → step S68 → step S75 → step S71. In step S71, the second torque reduction amount is selected.

  From time t4 to time t5 in FIG. 21, since the first torque down amount is smaller than the second torque down amount, the first torque down amount tends to increase and the second torque down amount tends to decrease. In the flowchart of step S61 → step S62 → step S63 → step S64 → step S68 → step S75 → step S70 → step S76, in step S76, the second torque reduction amount when the condition is satisfied is maintained. Alternatively, the second torque reduction amount when the condition is satisfied is decreased and changed with a gentle gradient.

  After time t5 in FIG. 21, the first torque down amount ≧ the second torque down amount, and the first torque down amount tends to increase and the second torque down amount tends to decrease. Then, the process proceeds from step S61 → step S62 → step S63 → step S64 → step S68 → step S72 → step S69. In step S69, the first torque reduction amount is selected.

  Therefore, as shown in the improved characteristics in FIG. 21, when compared with the characteristics before improvement in which only the parts protection control based on the first torque down amount is executed based on the set part protection priority flag, A more seamless torque change is achieved while maintaining the downshift side in the switching region. That is, the stability of the vehicle behavior is ensured.

Next, the effect will be described.
In the vehicle motor traction control device of the fifth embodiment, the following effects are obtained in addition to the effects (1), (2), (3) of the first embodiment and (6) of the fourth embodiment. be able to.

  (7) In the motor traction control unit, when the component protection control unit is preferentially selected by the priority selection unit, the first torque down amount by the component protection control unit is the second torque down amount by the stability control unit. In this case, when the first torque down amount by the component protection control unit tends to decrease and the second torque down amount by the stability control unit tends to increase, the torque down amount at the time when the condition is satisfied is held. The vehicle behavior can always be stabilized without causing torque tumble or slip-up.

  (8) In the motor traction control unit, when the component protection control unit is preferentially selected by the priority selection unit, the first torque down amount by the component protection control unit is the second torque down amount by the stability control unit. In this case, when the first torque down amount by the component protection control unit tends to decrease and the second torque down amount by the stability control unit tends to increase, the torque down amount at the time when the condition is satisfied has a gentle gradient. Therefore, seamless torque change is possible without causing torque tumble or slip-up, and vehicle behavior can always be stabilized.

  (9) In the motor traction control unit, when the component protection control unit is preferentially selected by the priority selection unit, the second torque reduction by the stability control unit is greater than the first torque reduction amount by the component protection control unit. If the amount is larger and the first torque down amount by the component protection control unit tends to increase and the second torque down amount by the stability control unit tends to decrease, the torque down amount when the condition is satisfied is Therefore, the vehicle behavior can always be stabilized without causing torque tumble or slip-up.

  (10) In the motor traction control unit, when the component protection control unit is preferentially selected by the priority selection unit, the second torque down by the stability control unit is greater than the first torque down amount by the component protection control unit. If the amount is larger and the first torque down amount by the component protection control unit tends to increase and the second torque down amount by the stability control unit tends to decrease, the torque down amount when the condition is satisfied is Since the change is made with a gentle gradient, the vehicle behavior can always be stabilized while maintaining the traction performance without causing torque tumble or slip-up.

  (11) A steering angle sensor 16 for detecting a steering angle is provided, and the motor traction control means decreases the change speed of the torque reduction amount as the steering angle increases, so that the steering angle is large and the turning behavior of the vehicle The more stable the vehicle is, the more stable the vehicle behavior can be.

  As mentioned above, although the motor traction control apparatus of the vehicle of this invention has been demonstrated based on Example 1-Example 5, it is not restricted to these Examples about a concrete structure, Each of a claim Design changes and additions are permitted without departing from the scope of the claimed invention.

  In the first to fifth embodiments, as the component protection control unit, the example in which the component protection is achieved by limiting the motor torque by the angular acceleration control has been described. For example, as illustrated in FIGS. The motor output and motor torque can be limited so that the total power used on the high-power unit side does not exceed the generated power and the carry-out from the secondary battery, or the battery (secondary battery) The motor output and the motor torque may be limited so that the current used on the higher power unit side does not exceed the set current value. In these cases as well, overcurrent can be prevented and parts can be protected.

  In Examples 1-5, although the example of slip ratio control was shown as a stability control part, for example, the slip amount control etc. which control the slip amount expressed by the rotation speed deviation of a driving wheel and a driven wheel to the optimal range etc. In short, any other control may be employed as long as it is a control unit that calculates the second torque down amount for stabilizing the vehicle behavior.

  In the first to third embodiments, the stability control unit shows an example pattern combined with the component protection control unit. In the fourth and fifth embodiments, the stability control unit shows an example pattern intervening during the component protection control. As shown, if the system has one or more stability control units as a motor traction control unit in addition to the component protection control unit, even a combination pattern with the component protection control unit may be a VDC system or other vehicle-mounted It may be an intervention pattern for TCS control in the control system.

As the road surface friction coefficient equivalent value estimating means in the second and third embodiments, means for estimating that the road surface μ is lower μ as the second torque down amount calculated by the second torque down amount calculating unit is smaller. However, if it is a means capable of estimating the road surface friction coefficient equivalent value, for example,
・ Means to express the combination of braking / driving force per each wheel speed and wheel load on the two-dimensional coordinates on each wheel, and to obtain the straight line representing these points to estimate the road friction coefficient ・ Drive slip Using the means to make the limited motor torque output value in the road equivalent to the road surface friction coefficient, the means to make the motor torque output value at the start of the slip equivalent to the road surface friction coefficient, the means to read the road surface μ information from the infrastructure, etc. Also good.

  In the first to fifth embodiments, an application example to a hybrid vehicle including one engine, two motor generators, and a power split mechanism has been shown. However, the motor traction control device of the present invention is a hybrid including another power unit structure. In short, any vehicle such as a car, an electric vehicle, a fuel cell vehicle, a motor 4WD vehicle, etc., which is equipped with at least one motor as a power source for driving the drive wheels can be applied.

1 is an overall system diagram illustrating a hybrid vehicle to which a motor traction control device according to a first embodiment is applied. FIG. 2 is a driving force performance characteristic diagram and a driving force conceptual diagram in a hybrid vehicle to which the motor traction control device of Embodiment 1 is applied. It is a contrast characteristic figure showing the braking force performance by regenerative cooperation in the hybrid car to which the motor traction control device of Example 1 was applied. It is an alignment chart which shows each vehicle mode in the hybrid vehicle to which the motor traction control device of Example 1 was applied. 1 is a block diagram illustrating a high-power unit of a hybrid vehicle according to a first embodiment. 3 is a flowchart illustrating a flow of a motor traction control process executed by the integrated controller according to the first embodiment. It is a figure which shows an example of the characteristic of the 1st torque down amount in angular acceleration control among the motor traction control in Example 1. FIG. It is a driving force coefficient characteristic diagram and a lateral force characteristic diagram of the longitudinal force showing the amount of TCS control for which slip ratio control is executed in the motor traction control in the first embodiment. It is a control block diagram which shows the conventional angular acceleration control. It is a figure which shows the driving wheel wheel speed characteristic, vehicle body speed characteristic, and cornering power characteristic in the conventional angular acceleration control. It is a time chart which shows each characteristic of the accelerator opening degree, vehicle speed, and driving wheel vehicle speed at the time of using the motor traction control based on the conventional angular acceleration. It is a figure which shows the driving wheel wheel speed characteristic in the motor traction control in Example 1, a vehicle body speed characteristic, and a cornering power characteristic. It is a block diagram which shows the driving force restriction | limiting calculation part which calculates the 2nd torque down amount by slip ratio control in the motor traction control apparatus of Example 2. FIG. FIG. 12 is a block diagram illustrating a driving force limit calculation unit that calculates a second torque down amount in slip ratio control in the motor traction control device according to the third embodiment. 10 is a flowchart illustrating a flow of a motor traction control process executed by an integrated controller according to a fourth embodiment. It is a figure which shows the resolver used as a rotation speed sensor. It is explanatory drawing which shows the condition where a VDC system operate | moves. It is explanatory drawing of the determination of the strong rear-wheel skid tendency in a VDC system, the judgment of the strong front-wheel skid tendency, the mitigating action of the rear-wheel skid tendency, and the mitigating action of the front-wheel skid tendency. Characteristics of part protection torque down amount and VDC torque down quantity when the part protection priority flag is set, part protection priority flag, conventional torque down quantity selection characteristics, torque down quantity selection in the present invention (Embodiment 4) It is a time chart which shows a characteristic. 10 is a flowchart illustrating a flow of a motor traction control process executed by an integrated controller according to a fifth embodiment. It is a comparison characteristic view of the torque-down amount characteristic before improvement (part protection priority) and the torque-down amount characteristic after improvement (Example 5). It is a block diagram which shows an example of the high electric power unit to which component protection control is applied. It is a block diagram which shows the other examples of the high electric power unit to which component protection control is applied.

Explanation of symbols

E engine
MG1 1st motor generator
MG2 Second motor generator (motor)
OS output sprocket
TM power split mechanism 1 engine controller 2 motor controller 3 power control unit 4 battery 5 brake controller 6 integrated controller 7 accelerator opening sensor 8 vehicle speed sensor 9 engine speed sensor 10 first motor generator speed sensor 11 second motor generator speed Sensor 12 Front left wheel speed sensor 13 Front right wheel speed sensor 14 Rear left wheel speed sensor 15 Rear right wheel speed sensor 16 Steering angle sensor 17 Master cylinder pressure sensor 18 Brake stroke sensor 19 Brake fluid pressure unit 20 Front left wheel wheel cylinder 21 Front right wheel wheel cylinder 22 Rear left wheel wheel cylinder 23 Rear right wheel wheel cylinder 24, 25, 26 Bidirectional communication line 27 Yaw rate sensor 28 Lateral acceleration sensor

Claims (11)

A motor for a vehicle, comprising: at least one motor provided in a power source for driving the driving wheels; and motor traction control means for detecting driving slip of the driving wheels and recovering the grip of the driving wheels by motor torque down control. In the traction control device,
The motor traction control means includes a component protection control unit that calculates a first torque down amount for component protection and a stability control unit that calculates a second torque down amount for stabilizing vehicle behavior. And
The motor traction control means selects the larger torque down amount as the control target torque down amount from the first torque down amount by the component protection control unit and the second torque down amount by the stability control unit. A motor traction control device for a vehicle. In the vehicle motor traction control device according to claim 1,
The component protection control unit is an angular acceleration control unit that detects a driving slip based on an angular acceleration of a driving wheel to which the motor is connected, and performs motor torque down control when the angular acceleration exceeds a set threshold. Vehicle motor traction control device. In the motor traction control device for a vehicle according to claim 1 or 2,
The stability control unit detects a driving slip based on a slip ratio of a driving wheel to which the motor is connected, and performs a motor torque down control so that the slip ratio is within an appropriate range for securing a road surface grip of the driving wheel. A motor traction control device for a vehicle which is a control unit. In the vehicle motor traction control device according to any one of claims 1 to 3,
A road surface friction coefficient equivalent value estimating means for estimating a road surface friction coefficient equivalent value is provided,
When the second torque reduction amount is calculated, the stability control unit gives a larger phase delay as the estimated road surface friction coefficient equivalent value indicates a lower friction coefficient. In the motor traction control device for a vehicle according to claim 4,
The stability control unit sets a phase delay upper limit value when it is estimated that the road surface friction coefficient equivalent value is an extremely low friction coefficient region having a predetermined value or less when calculating the second torque reduction amount. A motor traction control device for a vehicle. In the vehicle motor traction control device according to any one of claims 1 to 3,
The motor traction control means is provided with priority selection means for preferentially selecting one of the component protection control part and the stability control part,
In the motor traction control unit, when the component protection control unit is preferentially selected by the priority selection unit, the second torque down amount by the stability control unit is more than the first torque down amount by the component protection control unit. Is larger, the priority order is ignored and the second torque reduction amount is selected by the stability control unit. In the motor traction control device for a vehicle according to claim 6,
In the motor traction control unit, when the component protection control unit is preferentially selected by the priority selection unit, the first torque down amount by the component protection control unit is greater than or equal to the second torque down amount by the stability control unit. When the first torque down amount by the component protection control unit tends to decrease and the second torque down amount by the stability control unit tends to increase, the torque down amount at the time when the condition is satisfied is held. A motor traction control device for a vehicle. In the motor traction control device for a vehicle according to claim 6,
In the motor traction control unit, when the component protection control unit is preferentially selected by the priority selection unit, the first torque down amount by the component protection control unit is greater than or equal to the second torque down amount by the stability control unit. When the first torque down amount by the component protection control unit is decreasing and the second torque down amount by the stability control unit is increasing, the torque down amount when the condition is satisfied changes with a gentle gradient. A motor traction control device for a vehicle. The vehicle motor traction control device according to any one of claims 6 to 8,
In the motor traction control unit, when the component protection control unit is preferentially selected by the priority selection unit, the second torque down amount by the stability control unit is greater than the first torque down amount by the component protection control unit. When the first torque down amount by the component protection control unit tends to increase and the second torque down amount by the stability control unit tends to decrease, the torque down amount when the condition is satisfied is held. A motor traction control device for a vehicle. The vehicle motor traction control device according to any one of claims 6 to 8,
In the motor traction control unit, when the component protection control unit is preferentially selected by the priority selection unit, the second torque down amount by the stability control unit is greater than the first torque down amount by the component protection control unit. Is large, and when the first torque down amount by the component protection control unit tends to increase and the second torque down amount by the stability control unit tends to decrease, the torque down amount at the time when the condition is satisfied is gradually inclined. A motor traction control device for a vehicle, wherein In the motor traction control device for a vehicle according to claim 8 or 10,
A steering angle detecting means for detecting the steering angle is provided;
The motor traction control device for a vehicle is characterized in that the motor traction control means decreases the change speed of the torque down amount as the steering angle increases.

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