JP2009113772A - Braking force and driving force control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for a vehicle which can prevent occurrence of strange sound in a claw coupling mechanism when suppressing the vibration of a vehicle with the torque of a driving force source. <P>SOLUTION: The braking force and driving force control device for the vehicle includes: a driving force source; and the claw coupling mechanism arranged on a path ranging from the driving force source to a wheel, in which the torque of the driving force source is controlled based on a request driving power, and the torque of the driving force source can be controlled for suppressing the vibration of a vehicle. The control device is also provided with: a request torque calculation means (steps S1, S2 and S3) for calculating first torque from a request driving force; a vibration suppression torque calculating means (steps S4 and S5) for calculating second torque for suppressing the vibration of the vehicle; a composite torque calculation means (step S6) for calculating third torque based on the first torque and the second torque; and a torque correction means (step S6) for, when the positive/negative codes of the first torque and the positive/negative codes of the third torque are different, correcting the second torque so that those codes can be matched. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control device used in a vehicle, and more particularly to a braking force and driving force control device capable of suppressing the vertical vibration of the vehicle by the torque of a driving force source.

  In general, a vehicle is provided with a driving force source, and the torque of the driving force source is transmitted to wheels, and the torque of the driving force source is controlled based on the required driving force. On the other hand, the wheel is supported by a vehicle body via a suspension device, and if the road surface on which the vehicle travels is uneven, the vehicle may vibrate in the vertical direction. Thus, it is known to obtain a torque for suppressing the vibration of the vehicle and to perform control for adding or subtracting the torque to or from the torque based on the required driving force. An example of a vehicle configured to suppress vibrations in the vertical direction of the vehicle is described in Patent Document 1.

  In the vehicle described in Patent Document 1, wheels are supported on the vehicle body via a suspension device. In addition, each wheel, that is, the front wheel and the rear wheel is provided with a motor (in-wheel motor) inside the wheel, and the torque of each motor is transmitted to each wheel via a speed change mechanism. ing. It is described that this speed change mechanism can be constituted by a planetary gear mechanism. A stroke sensor or a vehicle height sensor is provided corresponding to each wheel, and the vertical vibration (bounding) of the vehicle body is detected by detecting the stroke amount of the suspension device for each wheel. Furthermore, in Patent Document 1, the target drive torque is calculated based on the amount of depression of the accelerator pedal. A target braking torque is calculated based on the depression amount of the brake pedal. The target drive torque is a target value for controlling the drive torque applied from each motor to each wheel, and the target brake torque is a target for controlling the brake torque applied from each motor to each wheel. Value. On the other hand, when the vibration of the vehicle body is detected, the braking torque or the driving torque applied to each wheel is calculated so that the force in the direction to cancel the vertical vibration acts on the vehicle body.

  That is, when suppressing the vibration of the vehicle body when the accelerator pedal is depressed and the target drive torque (positive torque) is generated by the motor, the vibration of the vehicle body is suppressed with respect to the target drive torque. Thus, the final target drive torque to be output from the motor is obtained. On the other hand, when suppressing the vibration of the vehicle body when the brake pedal is depressed and the target braking torque (negative torque) is generated by the motor, the vibration of the vehicle body relative to the target braking torque. The final target braking torque to be output from the motor is obtained by adding or subtracting the torque for suppressing the torque. In this way, vibration in the vertical direction of the vehicle body is suppressed, and fluctuations in the ground contact load of the wheel can be suppressed.

JP 2007-124868 A

  However, when the target torque obtained by depressing the accelerator pedal or the target braking torque obtained by depressing the brake pedal is in the vicinity of zero Newton meter, the damping torque is added to suppress vibration in the vertical direction of the vehicle body. Alternatively, when the final target drive torque and the final braking torque are obtained by subtraction, the final target drive torque itself may go back and forth between the positive side and the negative side with zero Newton meter as a boundary. Similarly, there is a possibility that the final target braking torque itself goes back and forth between the positive side and the negative side with zero Newton meter as a boundary. Thus, when the final target torque of the motor alternates between the positive side and the negative side, the torque in the forward and reverse directions is alternately transmitted to the rotating member provided on the path from the motor to the wheel. The Rukoto. Here, since the backlash is provided in the meshing portion of the planetary gear mechanism that constitutes the speed change mechanism, if the forward and reverse torques are alternately transmitted to the speed change mechanism, an abnormal noise due to the collision of the gears is generated. There was a problem of generating a rattling sound and rattling noise.

  The present invention has been made against the background described above, and can suppress the generation of abnormal noise in the meshing mechanism when controlling the torque of the driving force source to suppress the vibration in the vertical direction of the vehicle. An object of the present invention is to provide a control device for braking force and driving force of a vehicle.

  In order to achieve the above object, the invention of claim 1 is directed to a wheel supported by a vehicle body via a suspension device, a driving force source that generates torque transmitted to the wheel, and the wheel from the driving force source. And a meshing mechanism for transmitting torque by a meshing force in the circumferential direction centered on the axis, and the driving force based on the required driving force in the longitudinal direction of the vehicle A vehicle braking force and drive capable of obtaining a first torque to be output from a source and obtaining a second torque to be added to or subtracted from the first torque in order to suppress vibration in the vertical direction of the vehicle. In the force control device, output from the driving force source is performed by performing control for adding the second torque to the first torque and control for subtracting the second torque from the first torque. A torque calculating means for obtaining a provisional third torque to be outputted; a sign of torque to be output from the driving force source based on the acceleration request of the vehicle is positive; and the driving force based on the deceleration request of the vehicle Sign determination means for determining whether the sign of the first torque and the sign of the temporary third torque are the same when the sign of the torque to be output from the source is negative; When it is determined that the sign of the first torque is different from the sign of the temporary third torque, the sign of the first torque and the sign of the final third torque are Torque correction means for correcting the second torque is provided so that the reference numerals are the same.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, the torque correction means performs a correction to make the second torque relatively small, so that a positive / negative sign of the first torque is finally obtained. And means for making the sign of the third torque the same as the sign of the third torque.

  According to a third aspect of the present invention, in addition to the configuration of the first aspect, the torque control means prohibits control for adding the second torque to the first torque and control for subtracting the second torque from the first torque. In this way, there is provided means for making the sign of the first torque the same as the sign of the final third torque.

  According to the first aspect of the present invention, the first torque to be transmitted from the driving force source to the wheels is obtained based on the required driving force in the longitudinal direction of the vehicle. Further, in order to suppress vibration in the vertical direction of the vehicle, the second torque to be transmitted from the driving force source to the wheels is required. Further, a provisional third torque to be output from the driving force source is obtained by performing control for adding the second torque to the first torque and control for subtracting the second torque from the first torque. Then, it is determined whether or not the sign of the first torque is the same as the sign of the provisional third torque. Each torque has a positive sign when it is a power running torque or a driving torque, and a negative sign when it is a regenerative torque or a braking torque. Further, if it is determined that the sign of the first torque is different from the sign of the third torque, the sign of the first torque is the same as the sign of the temporary third torque. The second torque is corrected so that The sign of the third torque finally obtained by this correction changes in either the positive side or the negative side, and the sign of the third torque is the positive side and the negative side with zero Newton meter as a boundary. Can be prevented from going back and forth alternately. Therefore, it is possible to prevent positive torque and negative torque from being alternately transmitted to the meshing mechanism, and it is possible to prevent abnormal noise from being generated by the meshing mechanism.

  According to the second aspect of the invention, in addition to obtaining the same effect as the first aspect of the invention, by correcting the second torque to be relatively small, the positive and negative signs of the first torque and the temporary The sign of the third torque is made the same. Therefore, it is possible to more reliably prevent the final sign of the third torque from going back and forth between the positive side and the negative side with the zero Newton meter as a boundary.

  According to the invention of claim 3, in addition to obtaining the same effect as that of the invention of claim 1, the control for adding the second torque to the first torque and the control for subtracting the second torque from the first torque are prohibited. By doing so, the sign of the first torque can be made the same as the sign of the final third torque. Therefore, it is possible to more reliably prevent the final sign of the third torque from going back and forth between the positive side and the negative side with the zero Newton meter as a boundary.

  The vehicle in the present invention is a traveling body that travels on the ground, and vehicles include passenger cars, transport vehicles, trucks, buses, and the like. Further, the vehicle is provided with wheels, and the driving force is generated by transmitting the torque of the driving force source to the wheels. This driving force source may be either a single driving force source or a plurality of driving force sources. The plurality of driving force sources includes both meanings that a plurality of driving force sources having the same power generation principle are provided, or that a plurality of driving force sources having different power generation principles are provided. . Thus, a vehicle provided with a plurality of driving force sources having different power generation principles is a hybrid vehicle. Furthermore, when a single driving force source is used, or when a plurality of driving force sources having the same power generation principle are used, examples of the driving force source include an engine, an electric motor (electric motor), a hydraulic motor, and the like. Either can be used. On the other hand, when a plurality of driving force sources having different power generation principles are used, it is possible to use two or more types of driving force sources among, for example, an engine, an electric motor (electric motor), and a hydraulic motor.

  The engine is a power unit that burns fuel and converts its thermal energy into kinetic energy. As the engine, an internal combustion engine, specifically, a diesel engine, a gasoline engine, an LPG engine, or the like can be used. The electric motor is a driving force source that generates power when electric power is supplied from a power source. As this electric motor, it is possible to use a motor generator that has both a power running function for converting electric power into kinetic energy and a regeneration function for converting kinetic energy into electric power. Further, either an AC motor or a DC motor may be used as the motor, and for example, a three-phase AC motor can be used. The hydraulic motor is a device that converts kinetic energy of fluid into kinetic energy of a rotating member. In the present invention, the wheel is supported by the vehicle body via the suspension device, and the vehicle body and the wheel are configured to be relatively movable in the vertical direction, that is, the height direction of the vehicle. The vehicle body may have either a structure with a frame or a structure without a frame.

  Furthermore, when the wheels are provided at different positions in the front-rear direction of the vehicle, the wheels disposed forward in the front-rear direction are front wheels, and the wheels disposed rearward in the front-rear direction are rear wheels. The present invention provides a four-wheel drive vehicle configured to be able to transmit the torque of the driving force source to both the front wheels and the rear wheels, or the torque of the driving force source to either the front wheels or the rear wheels. The present invention is applicable to any two-wheel drive vehicle configured to be able to transmit. Further, when the present invention is used for a four-wheel drive vehicle, a vehicle having a configuration in which an electric motor that transmits torque to the front wheels and an electric motor that transmits torque to the rear wheels are separately provided may be used. Furthermore, in the present invention, a meshing mechanism is provided in a torque transmission path from the driving force source to the wheels. This meshing mechanism includes a mechanism for transmitting torque between a plurality of rotating elements by a meshing force in a circumferential direction centering on an axis. The meshing mechanism can be constituted by a concave portion having a radial depth around the axis and a convex portion having a radial height. Furthermore, the meshing mechanism can be constituted by a concave portion having a depth in the radial direction along the axis and a convex portion having a height in the direction along the axis.

  The meshing mechanism includes a gear mechanism, spline coupling, serration coupling, key coupling, and the like. The axes of the plurality of rotating elements may be arranged on the same axis, or the axes of the plurality of rotating elements may intersect each other. The rotating element includes a rotating shaft, a gear, a connecting drum, a carrier, a pulley, a sprocket, and the like. The gear mechanism includes a planetary gear mechanism, a selective gear mechanism, a constantly meshing gear mechanism, and the like. Specific examples of the power transmission device having the meshing mechanism include a transmission, a final reduction gear, a differential device, a power distribution device (transfer), a synchronization device (synchronizer), and the like. The transmission is a transmission device that can change a transmission gear ratio that is a ratio between an input rotation speed and an output rotation speed. The final reduction gear is a reduction gear arranged on the most downstream side in the power transmission path from the driving force source to the wheels, and is a transmission device that reduces the output rotation speed with respect to the input rotation speed. The differential device is a transmission device in which two output rotating members are connected to an input rotating member so that power can be transmitted, and a difference in rotational speed between the two output rotating members is allowed. The synchronizing device is a mechanism that connects two rotating members so that power can be transmitted after the rotational speeds of the input rotating member and the output rotating member are matched. In the present invention, the required driving force includes a driving force based on an acceleration request and a driving force (braking force) based on a deceleration request (braking request). In the present invention, the sign of the first torque to be output from the driving force source based on the acceleration request in the longitudinal direction of the vehicle is “positive”, and the output from the driving force source is based on the deceleration request in the longitudinal direction of the vehicle. The sign of the first torque to be performed is “negative”. In addition, when it is determined that the sign of the first torque is different from the sign of the provisional third torque, the second torque is corrected to be relatively small. ”Means that the torque is relatively lower than the second torque selected when the sign of the first torque is the same as the sign of the temporary third torque, or the torque range is Means relatively narrow. That is, it does not mean a specific torque value.

  FIG. 2 is a plan view showing the case where the present invention is used in a vehicle 1, specifically, a hybrid vehicle, and FIGS. 3 and 4 are schematic side views of the vehicle 1. A vehicle 1 shown in FIG. 2 is a four-wheel drive vehicle configured to be able to transmit torque of a driving force source to front wheels 2 and 3 and rear wheels 4 and 5. In the vehicle 1, an engine 6, a motor / generator (MG 1) 7, and a motor / generator (MG 2) 8 serving as driving force sources are mounted on the front portion of the vehicle body 27. 3 and 4, the left side portion of the vehicle body 27 is a front portion, and the right side portion of the vehicle body 27 is a rear portion. The engine 6 and the motor generators 7 and 8 are both connected to the front wheels 2 and 3 so that power can be transmitted. The engine 6 is a power unit that burns fuel and converts its thermal energy into kinetic energy. Here, a case where a gasoline engine is used will be described. The engine 6 is a known engine having an intake device, an exhaust device, a fuel injection device, an ignition device, and the like. The engine 6 can control the engine output, that is, the engine speed and the engine torque by controlling the intake air amount, the fuel injection amount, the ignition timing, and the like.

  The motor generators 7 and 8 are power units that have both a power running function that converts electrical energy into kinetic energy and a regeneration function that converts kinetic energy into electrical energy. As the motor generators 7 and 8, for example, a three-phase alternating current type can be used. The motor generator 7 includes a stator (not shown) fixed to a casing (not shown) and a rotation. A possible rotor (not shown). The motor generator 8 has a stator (not shown) fixed to a casing (not shown) and a rotatable rotor (not shown). Further, a power source 9 is provided for transferring power between the motor / generators 7 and 8 via the inverter 12. The power source 9 includes a power storage device and a generator. As the power storage device, a secondary battery, specifically, a battery or a capacitor can be used. As the generator, a fuel cell that generates an electromotive force by reacting hydrogen and oxygen can be used. Hereinafter, a case where a battery is used as the power source 9 will be described, and for convenience, the power source 9 will be referred to as “battery 9”. In this embodiment, even if the electric circuit is configured so that electric power can be directly transferred between the motor generator 7 and the motor generator 8 without going through the battery 9. Good.

  Next, the configuration of the power transmission path from the engine 6 and the motor generators 7 and 8 to the front wheels 2 and 3 will be described. In the power transmission path, a power distribution device 13, a reduction gear 14, and a final reduction gear 15 are provided. First, the power distribution device 13 is a device capable of distributing the power of the engine 6 to the motor generators 7 and 8 or the front wheels 2 and 3. The power distribution device 13 has three rotating elements that are differentially rotatable with respect to each other. More specifically, the power distribution device 13 includes an input element (not shown), a reaction force element (not shown), and an output element (not shown). The power distribution device 13 can be configured by a planetary mechanism, for example. As the planetary mechanism, a planetary gear mechanism or a planetary roller mechanism can be used. This planetary gear mechanism is a transmission device that transmits power by the meshing force between gears. For example, when a single pinion type planetary gear mechanism is used as the planetary gear mechanism, it is possible to arrange a sun gear and a ring gear on the same axis and to provide a carrier meshing with the sun gear and the ring gear. The carrier that is the input element is connected to the crankshaft of the engine 6, the sun gear that is the reaction force element is connected to the rotor of the motor / generator 7, and the ring gear that is the output element is the input element of the speed reducer 14. Connected. On the other hand, the planetary roller mechanism is a transmission device that transmits power by the shearing force of traction oil. In the power distribution device 13 configured as described above, the speed ratio between the input element and the output element can be continuously controlled by controlling the rotation speed of the reaction force element. That is, the power distribution device 13 also has a function as a continuously variable transmission.

  The motor / generator 8 is connected to an input element of the speed reducer 14 so that power can be transmitted. The speed reducer 14 can be constituted by, for example, a gear transmission. Moreover, the reduction gear 14 can also be comprised combining a winding transmission device and a gear transmission. It is also possible to provide a speed reducer (not shown) different from the speed reducer 14 in the power transmission path between the motor / generator 8 and the input element of the speed reducer 14. This reduction gear can also use a gear type reduction gear. Further, the input element of the final reduction gear 15 is connected to the output element of the reduction gear 14. As the final reduction gear 15, a gear mechanism type can be used. That is, the final reduction gear 15 includes a ring gear (not shown) that meshes with a pinion gear (not shown) of the reduction gear 14, a differential case (not shown) that rotates integrally with the ring gear, and a pinion gear (not shown) attached to the differential case. ) And a side gear (not shown) attached to a pinion gear (not shown). Front wheels 2 and 3 are connected to side gears, which are output elements of the final reduction gear 15, via axle shafts (drive shafts) 16 and 17. Specifically, a front wheel (right front wheel) 2 is connected to the axle shaft 16, and a front wheel (left front wheel) 3 is connected to the axle shaft 17. The final reduction gear 15 functions as a differential device that allows relative rotation of the two axle shafts 16 and 17 in addition to the function as a reduction gear that lowers the rotation speed of the output element than the rotation speed of the input element. Combines functions.

  Furthermore, a motor / generator 18 is mounted on the rear portion of the vehicle 1 in the front-rear direction. The motor / generator 18 may have the same configuration and function as the motor / generators 7 and 8 described above. A battery 9 is connected to the motor / generator 18 via the inverter 12. That is, an electric circuit capable of transferring power between the battery 9 and the motor / generator 18 is configured. The motor / generator 18 has a stator (not shown) and a rotor (not shown). A rear wheel (right rear wheel) 4 is connected to the rotor via an axle shaft (drive shaft) 19, and a rear wheel (left rear wheel) 5 is connected to the rotor via an axle shaft (drive shaft) 20. It is connected. A reduction gear (not shown) can be provided in the torque transmission path from the rotor of the motor / generator 18 to the axle shafts 19 and 20. As this speed reducer, for example, a gear mechanism type speed reducer can be used. With this reduction gear, the rotational speed of the axle shafts 19 and 20 can be reduced with respect to the rotational speed of the motor / generator 18 to amplify the torque.

  In the present invention, as shown in FIGS. 2, 3, and 4, the front wheels 2, 3 and the rear wheels 4, 5 are supported by a vehicle body 27 via a suspension device (suspension) 30. More specifically, an independent suspension device is used in which the front wheels 2 and 3 and the four rear wheels 4 and 5 can move up and down independently of the vehicle body 27. For example, as the suspension device 30 that supports the front wheels 2 and 3, a double wishbone type or strut type suspension device can be used. On the other hand, as the suspension device 30 for supporting the rear wheels 4 and 5, a double wishbone type or semi-trailing arm type suspension device can be used. Each suspension device 30 has a spring (not shown) that expands and contracts in the vertical direction of the vehicle 1. Furthermore, a braking device (not shown) is provided that applies a braking force to each wheel by operating the brake pedal. This braking device has a master cylinder, a hydraulic circuit, a wheel cylinder provided for each wheel, and the like.

  Next, the control system of the vehicle 1 will be described. An electronic control device 21 is provided as a controller for controlling a system mounted on the vehicle 1. The electronic control device 21 receives signals such as the vehicle speed, the engine speed, the amount of charge of the battery 9, and the motor generators 7, 8, and 18. Further, the electronic control device 21 includes a signal from the vehicle body vibration detection sensor 22, a signal from the wheel vibration detection sensor 23, an operation signal from the acceleration request generation device 24, a signal from the road condition detection sensor 25 for detecting a road condition, and a navigation system 26. And the operation signal of the deceleration request generator 28 are input. The vehicle body vibration detection sensor 22 is a sensor that detects vertical vibrations of the vehicle body, in other words, bounce. The vehicle body vibration detection sensor 22 can separately detect a change in the vertical stroke of the suspension device provided for each wheel, and can detect the vertical vibration of the vehicle body based on the detection result. It is configured. The wheel vibration detection sensor 23 is a sensor that detects vertical vibrations of the front wheels 2, 3 and the rear wheels 4, 5 with respect to the vehicle body, and is based on the sprung acceleration of the spring constituting each suspension device 30. It is configured to detect vertical vibrations of the front wheels 2 and 3 and the rear wheels 4 and 5.

  The acceleration request generator 24 is a device that is operated by the hand or foot of an occupant of the vehicle 1. Specific examples of the acceleration request generator 24 include a lever, a button, a knob, a switch, a liquid crystal touch panel, and a pedal. In this embodiment, it is assumed that an accelerator pedal operated by a foot is used as the acceleration request generator 24, and hereinafter referred to as an “accelerator pedal 24” for convenience. Further, the deceleration request generation device 28 is a device that is operated by the hand or foot of an occupant of the vehicle 1. Specific structures of the deceleration request generator 28 include a lever, a button, a knob, a switch, a liquid crystal touch panel, a pedal, and the like. In this embodiment, it is assumed that a brake pedal operated by a foot is used as the deceleration request generating device 28, and hereinafter referred to as “brake pedal 28” for convenience. Furthermore, the road condition detection sensor 25 is constituted by, for example, an infrared camera, and is a sensor that detects road surface unevenness. Further, the navigation system 26 has a function of detecting the current position of the vehicle 1, a function of inputting a destination of the vehicle 1, a function of searching or inputting a travel route to the destination of the vehicle 1, a situation of the travel route, weather, and the like. And a function of storing a travel locus of the vehicle 1. The current position of the vehicle 1 can be obtained by autonomous navigation or radio navigation. Autonomous navigation is a method for detecting the current position of the vehicle 1 based on map data recorded on an external storage device (CD-ROM, DVD, etc.) attached to the vehicle 1 and the rotation angle of wheels. It is obtained from signals such as a steering angle sensor and a rotation speed sensor for detecting the rotation speed of the wheel.

  On the other hand, radio navigation refers to a vehicle that can be placed on a map by exchanging signals between external equipment existing outside the vehicle 1 (such as the ground, roads, and outer space) and a receiver mounted on the vehicle 1. The current position of 1 is detected. In radio navigation, the current position of the vehicle 1 is detected by receiving radio waves (signals) from GPS (global positioning system: artificial satellites) and radio waves (signals) transmitted from beacons or sign posts installed on the ground. To do. In this way, by detecting the current position of the vehicle 1 on the map, road conditions ahead of the travel route of the vehicle 1, specifically, curves, road surface irregularities, uphill roads, downhill roads, gravel roads, It can detect the friction coefficient of mountain roads and road surfaces.

  Next, an example of control that can be executed by the vehicle 1 will be described. First, control when an acceleration request in the front-rear direction of the vehicle 1 is generated will be described. In this case, the required driving force in the vehicle 1 is determined based on the vehicle speed and the degree of acceleration request. The degree of the acceleration request is determined based on the operation state of the accelerator pedal 24, specifically, the depression amount of the accelerator pedal 24 (accelerator opening), the depression speed of the accelerator pedal 24, and the like. Further, based on the required driving force, the target output of the engine 6 and the target outputs of the motor generators 7, 8, 18 are obtained. A map used when the actual output of the engine 6 is brought close to the target output is stored in the electronic control unit 21. This map is a map in which the target engine speed and the target engine torque are determined based on the optimal fuel consumption line for optimally controlling the fuel consumption of the engine 6. Then, when the actual output of the engine is brought close to the target output, the target engine speed and the target engine torque shown in the map are used. The gear ratio of the power distribution device 13 is controlled in order to bring the actual engine speed of the engine 6 close to the target engine speed.

  Specifically, when the engine torque is transmitted to the input element of the power distribution device 6 and the motor / generator 7 takes charge of the reaction force of the engine torque, the engine 6 is controlled by controlling the rotational speed of the motor / generator 7. It is possible to bring the actual engine speed close to the target engine speed. In parallel with the control of the actual rotational speed of the engine 6, at least one of the intake air amount, ignition timing, and fuel injection amount of the engine 6 is set so that the actual torque of the engine 6 approaches the target engine torque. Matters are controlled. In this way, when the speed ratio of the power distribution device 13 is controlled steplessly, when the motor / generator 7 responsible for the reaction force of the engine torque rotates forward, the motor / generator 7 is regeneratively controlled. That is, a part of the power of the engine 6 is converted into electric power by the motor / generator 7, and the electric power is charged to the battery 9 via the inverter 12. On the other hand, when the motor / generator 7 responsible for the reaction force of the engine torque rotates in the reverse direction, the motor / generator 7 is subjected to power running control. That is, the electric power of the battery 9 is supplied to the motor / generator 7 via the inverter 12, and the motor / generator 7 is driven as an electric motor. In this way, the power of the engine 6 is transmitted to the speed reducer 14 via the power distribution device 13.

  On the other hand, when part of the power corresponding to the required driving force is borne by the motor / generator 8, the electric power of the battery 9 is supplied to the motor / generator 8 via the inverter 12, and the motor / generator 8 serves as the electric motor. Driven. In this way, the torque input to the speed reducer 14 is transmitted to the front wheels 2 and 3 via the axle shafts 16 and 17, respectively, and a driving force is generated at the front wheels 2 and 3. Further, when a part of the power corresponding to the required driving force is borne by the motor / generator 18, the electric power of the battery 9 is supplied to the motor / generator 18 via the inverter 12, and the motor / generator 18 serves as the electric motor. To drive. The torque of the motor / generator 18 is transmitted to the rear wheels 4 and 5 via the axle shafts 19 and 20, respectively, and a driving force is generated at the rear wheels 4 and 5. It is also possible to stop or idle the engine 6 and perform power running control on at least one of the motor generators 8 and 18.

  Next, control when a deceleration request in the front-rear direction of the vehicle 1 occurs, that is, when the brake pedal 28 is depressed or the accelerator pedal 24 is returned will be described. In this case, at least one of the motor generator 8 and the motor generator 18 can function as a generator. In other words, the power of the front wheels 2 and 3 is transmitted to the motor / generator 18 via the speed reducer 14, and regenerative control is performed by the motor / generator 18, and the generated power is charged to the battery 9 via the inverter 12. be able to. Further, the motor / generator 18 performs regenerative control by the power of the rear wheels 4 and 5, and the generated power can be charged to the battery 9 via the inverter 12. In this way, a regenerative braking force can be applied to the front wheels 2, 3 or the rear wheels 4, 5. The braking force corresponding to the deceleration request can be borne by the braking force of a braking device (not shown). Further, when the motor / generator 7 is subjected to power running control and is responsible for the reaction force of the engine torque, a part of the power of the engine 6 is transmitted to the motor / generator 8 to perform regenerative control, and the generated electric power is transmitted to the motor / generator 7. It is also possible to supply Furthermore, when a deceleration request in the front-rear direction of the vehicle 1 is generated, the power of the front wheels 2 and 3 is transmitted to the engine 6 via the speed reducer 14 and the power distribution device 13 to generate an engine braking force.

  Furthermore, the control which suppresses the vibration in the up-down direction of the vehicle 1 is demonstrated. Here, for the sake of convenience, a case where vibration in the vertical direction of the vehicle 1 is suppressed by controlling the torque of the motor generators 8 and 18 will be taken up. First, a case where an acceleration request is generated in the vehicle 1 will be described. For example, when the amount of sprung displacement detected by the vehicle body vibration sensor 22 exceeds a threshold value stored in advance in the electronic control unit 21, it is determined that bounce has occurred in the vehicle body 27, and the vehicle body vibration sensor 22 is detected. When the sprung displacement amount detected by the above is less than or equal to a threshold value stored in advance in the electronic control unit 21, a control program is stored in the electronic control unit 21 so as to determine that no bouncing has occurred in the vehicle body 27. Stored. More specifically, when the sprung displacement amount is positive, it is determined that the vehicle body 27 is bounced up, and when the sprung displacement amount is negative, the vehicle body 27 is bounced up and down. to decide.

  And when the bounce which raises the vehicle body 27 generate | occur | produces, the bounding of the vehicle body 27 can be suppressed by the following control. Specifically, as shown in FIG. 3, the motor / generator 8 is configured such that a driving force ΔF1 for damping is added to the driving force generated at the front wheels 2 and 3 based on the required driving force. Torque is controlled. That is, the driving force of the front wheels 2 and 3 increases. Further, the torque of the motor / generator 18 is controlled so that the braking force ΔF2 for damping is added to the driving force generated at the rear wheels 4 and 5 based on the required driving force. That is, the driving force of the rear wheels 4 and 5 is reduced. In this way, when forces are generated that are opposite to each other in the front-rear direction of the vehicle 1 and are separated from each other, a downward force is generated with respect to the vehicle body 27 and the upward movement of the vehicle body 27 is suppressed.

  On the other hand, when the bounce that the vehicle body 27 descends occurs, the bounce of the vehicle body 27 can be suppressed by the following control. As shown in FIG. 4, when the driving force is generated at the front wheels 2 and 3 based on the required driving force, the motor generator 8 is configured so that the braking force ΔF2 for damping is applied to the front wheels 2 and 3. Torque is controlled. That is, the driving force of the front wheels 2 and 3 is reduced. Further, when the driving force is generated at the rear wheels 4 and 5 based on the required driving force, the torque of the motor / generator 18 is controlled such that the driving force ΔF1 for damping is added. That is, the driving force of the rear wheels 4 and 5 increases. In this way, when forces that are opposite to each other in the front-rear direction of the vehicle 1 and that approach each other are generated, an upward force is generated with respect to the vehicle body 27 and the lowering of the vehicle body 27 is suppressed.

  Next, control when the front wheels 2 and 3 and the rear wheels 4 and 5 vibrate in the vertical direction with respect to the vehicle body 27 will be described. First, when the front wheels 2 and 3 ride on the convex portions of the road surface and receive an impact, the ground load of the front wheels 2 and 3 increases. Therefore, as shown in FIG. 3, the torque of the motor / generator 8 is controlled so that the driving force ΔF1 is added to the driving force generated at the front wheels 2 and 3 in response to the required driving force. That is, the driving force generated at the front wheels 2 and 3 is increased. By this control, the front wheels 2 and 3 are pushed up by the upward force acting on the contact surface between the front wheels 2 and 3 and the road, so that the front wheels 2 and 3 can move up while following the convex portion. In this manner, the ground load on the front wheels 2 and 3 is reduced, and the grounding performance is improved. On the other hand, when the rear wheels 4 and 5 ride on the bumps on the road surface and receive an impact, the ground load on the rear wheels 4 and 5 increases. Therefore, the torque of the motor / generator 18 is controlled so as to give the braking force ΔF2 to the driving force generated at the rear wheels 4 and 5 in response to the required driving force. That is, the driving force generated at the rear wheels 4 and 5 is reduced. By this control, the rear wheels 4 and 5 are pushed up by the upward force acting on the contact surface between the rear wheels 4 and 5 and the road, so that the rear wheels 4 and 5 can move up while following the convex portion. Become. In this way, the grounding load of the rear wheels 4 and 5 is reduced, and the grounding performance is improved.

  On the contrary, the control when the front wheels 2 and 3 are lowered with respect to the vehicle body when the front wheels 2 and 3 are shifted from the convex portion to the concave portion of the road surface will be described. In this case, as shown in FIG. 4, the torque of the motor / generator 8 is controlled so that the braking force ΔF2 is applied to the torque generated in the front wheels 2 and 3 corresponding to the required driving force. That is, the driving force generated at the front wheels 2 and 3 is reduced. By this control, a downward force is applied to the front wheels 2 and 3, so that the front wheels 2 and 3 can descend while following the recess. In this way, the ground load of the front wheels 2 and 3 is increased, and the grounding performance is improved. On the other hand, control when the rear wheels 4 and 5 are lowered with respect to the vehicle body 27 by the rear wheels 4 and 5 moving from the convex portion to the concave portion of the road surface will be described. In this case, the torque of the motor / generator 18 is controlled so as to give the driving force ΔF1 to the driving force generated at the rear wheels 4 and 5 in response to the required driving force. That is, the driving force generated at the rear wheels 4 and 5 is increased. By this control, a downward force is applied to the rear wheels 4 and 5, so that the rear wheels 4 and 5 can descend while following the recess.

  In this way, the grounding load of the rear wheels 4 and 5 is increased, and the grounding performance is improved. In addition, control which suppresses the vibration in the up-down direction of the vehicle body 27 (first vibration suppression control) or control which suppresses the vibration in the vertical direction of the wheel (second vibration suppression control) is executed. Both controls are not executed simultaneously (in parallel). As described above, when the acceleration request is generated in the vehicle 1 and the motor generators 8 and 18 are driven as electric motors and the vibration of the vehicle 1 is suppressed, the motor obtained based on the acceleration request is obtained. A torque for suppressing vibration is added to or subtracted from the power running torque (positive torque) of the generators 8 and 18.

  On the other hand, when the deceleration request | requirement has generate | occur | produced in the vehicle 1, it is also possible to perform control which suppresses the vibration in the up-down direction of the vehicle 1. FIG. More specifically, when a deceleration request is generated in the vehicle 1 and regenerative control is being performed by the motor generators 8 and 18, the vibration in the vertical direction of the vehicle 1 is suppressed based on the deceleration request. Control for adding or subtracting torque for suppressing vibration to regenerative braking torque (negative torque) generated by motor generators 8 and 18 is performed. The torque (damping torque) to be output from the motor / generator with respect to the vibration amount of the vehicle body 27 or the vibration amount of each wheel is mapped in advance and stored in the electronic control device 21.

  Incidentally, a reduction gear 14 and a final reduction gear 15 are provided in the power transmission path from the motor / generator 8 to the front wheels 2 and 3, and the meshing portions of the gears constituting the reduction gear 14 and the final reduction gear 15 are provided. A backlash is formed. Here, as described above, the final torque is obtained by adding or subtracting the second torque for suppressing the vibration to the first torque of the motor / generator 8 obtained based on the acceleration request or the deceleration request. When three torques are obtained, the final third torque may be alternately switched between a positive torque and a negative torque with zero Newton meter as a boundary. Then, there is a possibility that an abnormal noise, that is, an impact sound and a rattling noise may be generated at the meshing portion of the gears.

  Therefore, in this embodiment, when controlling the torque of the motor / generator to suppress the vibration in the vertical direction of the vehicle 1, the power transmission path from the motor / generator to the wheels is different at the meshing portion of the gears. Control to suppress the generation of sound is executed. An outline of a control example for suppressing the generation of the abnormal noise will be described with reference to the control system of FIG. In FIG. 1, the torque control of the motor / generator 8 is excluded for convenience. First, the required driving force is obtained based on the vehicle speed and the accelerator opening, and the driving torque (required torque) is obtained based on the required driving force (step S1). This driving torque includes all of the engine torque and the torques of the motor generators 8 and 18. Note that a map is stored in advance in the electronic control device 21 in order to perform the process of step S1. Subsequent to step S1, a process (smoothing process) for slowly changing the obtained drive torque is performed (step S2). This slow change process is a process for suppressing drivability deterioration due to a sudden change in drive torque. Specifically, it is possible to prevent a sudden change in driving force and a shock, or an abnormal noise. Following this step S2, torque (engine direct torque) borne by the engine 6 is subtracted from the drive torque that has been subjected to the gradual change process, and the remainder is calculated as the reference torque (base MG2 torque) of the motor generator 8. (Step S3). This reference torque corresponds to the first torque described above.

  On the other hand, the torque of the motor / generator 8 for suppressing the vertical vibration of the vehicle 1, that is, the damping torque is obtained (step S4). The processing in step S4 is as described above, and this vibration damping torque is the second torque described above. Subsequent to step S4, a process for setting an upper limit and a lower limit for the damping torque is performed (step S5). The upper limit and the lower limit are set to avoid inconvenience caused by adding or subtracting the damping torque. This upper limit is the maximum value of the damping torque that can be added by the motor / generator 8. The lower limit is the maximum value of the damping torque that can be subtracted by the motor / generator 8.

  The lower limit and the upper limit can be determined, for example, based on the charge amount of the battery 9. Specifically, when the charge amount of the battery 9 is relatively large, the absolute value of the lower limit can be set relatively small compared to the case where the charge amount of the battery 9 is relatively small. On the other hand, when the charge amount of the battery 9 is relatively large, the upper limit absolute value can be set relatively larger than when the charge amount of the battery 9 is relatively small. As described above, by setting the upper limit and the lower limit based on the charge amount of the battery 9, the inconvenience of discharging or overcharging the battery 9 can be avoided. The lower limit and the upper limit may be changed according to a change in the charge amount of the battery 9, or may be determined as a fixed value in advance. The above lower limit and upper limit are obtained experimentally or by simulation and stored in the electronic control unit 21.

  In this way, the final third torque of the motor / generator 8 is obtained by performing the process of adding the damping torque set with the upper limit and the lower limit to the reference torque and the process of subtracting it from the reference torque ( Step S6), this control routine is terminated. In the control example of FIG. 1, the order of the timing of executing step S3 and the timing of executing steps S4 and S5 is not questioned. That is, the timing for executing step S3 may be the same as the timing for executing steps S4 and S5, or after executing step S3, it may execute steps S4 and S5, or before executing step S3. Alternatively, steps S4 and S5 may be executed.

  In step S6 described above, any one of the first to third subroutines can be selected. First, an example of the first subroutine will be described based on the time chart of FIG. FIG. 5 shows the drive torque A1 and the reference torque B1 before the slow change process is performed. The reference torque B1 is a value obtained by subtracting the engine direct torque from the drive torque A1 that has been subjected to the gradual change process. Further, an upper limit C1 and a lower limit C2 having a predetermined width T1 with respect to the reference torque B1 are shown. The upper limit C1 and the lower limit C2 have the same width T1. In FIG. 5, the upper limit C1 is a value that is greater than the reference torque B1 for positive torque or a value that is smaller than the reference torque B1 for negative torque. On the other hand, the lower limit C2 is a value that is smaller than the reference torque B1 in the positive torque, or a value that is larger than the reference torque B1 in the negative torque. Further, the damping torque D1 obtained in step S4 is shown between the lower limit C2 and the upper limit C1. Further, before the time t2, the reference torque B1 is a positive torque (power running torque), becomes zero Newton at the time t2, and after the time t2, the reference torque B1 becomes a negative torque (regenerative torque). Furthermore, before the time t1 before the time t2, the upper limit C1 and the lower limit C2 are both positive torques.

  On the other hand, before and after time t1, the lower limit C2 is switched from positive torque to negative torque. Furthermore, from time t1 to time t3 after time t2, the upper limit C1 is a positive torque and the lower limit C2 is a negative torque. On the other hand, before and after time t3, the upper limit C1 is switched from positive torque to negative torque. Therefore, as shown in FIG. 5, if the reference torque B1 changes, the damping torque D1 is added to the reference torque B1 or the damping torque D1 is subtracted from the reference torque B1. When the third torque is calculated, there is a possibility that the provisional third torque is alternately switched between positive and negative with zero Newton meter as a boundary. Therefore, in the first subroutine that is executed by proceeding to step S6, the process of adding the damping torque D1 with the upper and lower limits set between the time t1 and the time t3 to the reference torque B1, and the reference torque B1 The process of subtracting the damping torque D1 from is prohibited. In other words, in the first subroutine, a process for handling the reference torque B1 obtained in step S3 as the final third torque of the motor / generator 8 is performed.

  Next, a second subroutine example that can be executed in step S6 will be described based on the time chart of FIG. Also in FIG. 6, the time-dependent change of the same parameter as FIG. 5 is shown. In the time chart of FIG. 6, before the time t1 and after the time t3, the absolute value of the reference torque B1 exceeds the torque width T1 from the reference torque B1 to the upper limit C1 or the lower limit C2. Therefore, in the second subroutine, before the time t1 and after the time t3, the control for adding the damping torque to the reference torque B1 and the control for subtracting the damping torque from the reference torque B1 are performed. Third torque is required.

  On the other hand, in the time chart of FIG. 6, between time t1 and time t2, the absolute value of the reference torque B1 is equal to or less than the torque width T1 from the reference torque B1 to the lower limit C2. Further, between time t2 and time t3, the absolute value of the reference torque B1 is equal to or less than the torque width T1 from the reference torque B1 to the upper limit C2. For this reason, if the damping torque D1 is added to or subtracted from the reference torque B1 to obtain the provisional third torque, the provisional third torque may be switched alternately between positive and negative at the zero Newton meter boundary. is there. Therefore, when the second subroutine is selected, the range between the upper limit C1 ′ and the lower limit C2 ′ is larger than the range between the upper limit C1 and the lower limit C2 before the time t1 and after the time t3 from the time t1 to the time t3. It is set relatively small (narrow). Then, between time t1 and time t3, the damping torque D1 is added or subtracted in a relatively narrow range with respect to the reference torque D1, and the final third torque of the motor / generator 8 is obtained. Perform processing.

  Next, the third subroutine will be described. Also in this third subroutine, the same processing as the first subroutine is performed before time t1 and after time t3. Further, when the third subroutine is selected, the range of the damping torque D1 to be added to the reference torque B1 is set within the range T1 of the upper limit C1 and the reference torque B1 from time t1 to time t2. The width of the damping torque D1 to be subtracted from the reference torque B1 is relatively reduced within the width T1 of the lower limit C2. On the other hand, from time t2 to time t3, the width of the damping torque D1 to be subtracted from the reference torque B1 is set within the width T1 of the lower limit C2, and the damping torque D1 to be added to the reference torque B1. Is made relatively smaller within the width T1 of the upper limit C1 from the reference torque B1. Thus, when the third subroutine is selected, between time t1 and time t3, the width of the torque added to the reference torque B1 is different from the width of the torque subtracted from the reference torque B1.

  In this way, regardless of which of the first to third subroutines is selected in step S6, the vibration damping torque D1 goes back and forth between positive torque and negative torque with zero Newton meter as a boundary. Can be prevented. Therefore, when controlling the torque of the motor / generator 8 to suppress the vibration in the vertical direction of the vehicle 1, it is possible to avoid the generation of abnormal noise at the meshing portion of the gears. In the case where a gear meshing portion is provided in the path from the motor / generator 18 to the rear wheels 4 and 5, the torque of the motor / generator 18 is set so as to prevent noise from occurring in the gear meshing portion. It is also possible to perform control based on the same principle as the control example described with reference to FIGS.

  Further, in this specific example, it is also possible to suppress the vehicle 1 from vibrating in the vertical direction by controlling the torque transmitted from the engine 6 to the front wheels 2 and 3. For example, the target engine torque is obtained based on the required driving force, and the control to add the damping torque to the target engine torque or the control to subtract the damping torque from the target engine torque to obtain the final engine torque It becomes. When the final engine torque is a positive torque, it is possible to suppress abnormal noise at the meshing portion of the gears by controlling the intake air amount, the fuel injection amount, the ignition timing, and the like. Further, when the final engine torque is a negative torque, if the engine brake force is controlled by adjusting the intake air amount, the meshing portion of the gears constituting the power distribution device 13 and the gear constituting the speed reducer 15 It is possible to suppress abnormal noise at the meshing portion between the gears and the meshing portion between the gears constituting the final reduction gear 15. 5 and 6 show the case where the basic torque B1 is switched from positive torque to negative torque. However, in the control example of FIG. 1, the basic torque B1 is changed from negative torque to positive torque. It is also possible to prevent the final torque from alternating between a positive torque and a negative torque when switching to.

  Further, the present invention provides a power train having a configuration in which four motors / generators are separately provided to transmit power to the left and right front wheels and the left and right rear wheels, that is, so-called in-wheel motor type four wheels It can also be applied to driving vehicles. This vehicle is an electric vehicle not provided with an engine. Then, when a speed reducer with a gear mechanism is used in the power transmission path from each motor / generator to the wheels, the torque of the four motors / generators is controlled separately using the principle of this specific example. Then, when the torque of each motor is controlled separately to suppress the vibration in the vertical direction of the vehicle, it is possible to prevent the generation of abnormal noise at the meshing portion of the gears constituting the speed reducer. Furthermore, the present invention is also applicable to a vehicle (electric vehicle) in which a motor / generator is provided as a driving force source and an engine is not provided. In this case, the present invention can also be applied to a two-wheel drive vehicle configured such that the torque of the motor / generator is transmitted to either the front wheels or the rear wheels. When this motor / generator torque is transmitted to the wheels via the transmission and final reduction gear, abnormal noise is generated at the meshing part of the gears constituting the transmission or final reduction gear. Can be prevented.

  Here, the correspondence between the functional means shown in FIG. 1 and the configuration of the present invention will be described. Steps S1 to S6 correspond to torque calculating means in the present invention, and step S6 is sign determining means. It corresponds to torque correction means. The suspension device 30 corresponds to the suspension device in the present invention, and the vehicle body 27 corresponds to the vehicle body in the present invention. The front wheels 2 and 3 and the rear wheels 4 and 5 correspond to the wheels in the present invention, the engine 6 and the motor generators 8 and 18 correspond to the driving force source in the present invention, the power distribution device 13 and the speed reducer 14 and A meshing portion between the gears provided in the final reduction gear 15 corresponds to the meshing mechanism in the present invention. Further, the basic torque B1 obtained in step S3 corresponds to the first torque in the present invention, and the damping torque D1 obtained in step S4 corresponds to the second torque in the present invention, and is finally obtained in step S6. This torque corresponds to the third torque in the present invention.

It is a flowchart which shows the example of control of this invention. FIG. 2 is a planar conceptual diagram illustrating a configuration of a vehicle that can execute the control example of FIG. 1. FIG. 3 is a side view of the vehicle shown in FIG. 2 when vibration suppression control is performed. FIG. 3 is a side view of the vehicle shown in FIG. 2 when vibration suppression control is performed. It is a time chart corresponding to the subroutine performed with the flowchart of FIG. It is a time chart corresponding to the subroutine performed with the flowchart of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2, 3 ... Front wheel, 4, 5 ... Rear wheel, 8, 18 ... Motor generator, 13 ... Power distribution device, 14 ... Reduction gear, 15 ... Final reduction gear, 27 ... Car body, 30 ... Suspension device .

Claims (3)

A wheel supported by the vehicle body via a suspension device, a driving force source that generates torque to be transmitted to the wheel, a torque transmission path from the driving force source to the wheel, and centered on the axis And a meshing mechanism that transmits torque by a circumferential meshing force, and obtains a first torque to be output from the driving force source based on a requested driving force in the longitudinal direction of the vehicle, and In a control device for a braking force and a driving force of a vehicle capable of obtaining a second torque to be added to or subtracted from the first torque in order to suppress vibration in a direction,
Torque calculating means for obtaining a provisional third torque to be output from the driving force source by performing control for adding the second torque to the first torque and control for subtracting the second torque from the first torque;
When the sign of the torque to be output from the driving force source based on the acceleration request of the vehicle is positive and the sign of the torque to be output from the driving force source is negative based on the deceleration request of the vehicle Sign determination means for determining whether the sign of the first torque is the same as the sign of the provisional third torque;
If it is determined that the sign of the first torque is different from the sign of the temporary third torque, the sign of the first torque and the sign of the final third torque And a torque correction means for correcting the second torque so as to be the same as each other.   The torque correction means includes means for making the sign of the first torque the same as the sign of the final third torque by performing correction to relatively reduce the second torque. The control device for braking force and driving force of a vehicle according to claim 1.   The torque control means prohibits control for adding the second torque to the first torque and control for subtracting the second torque from the first torque, so that the positive and negative signs of the first torque and the final The vehicle braking force and driving force control device according to claim 1, further comprising means for making the sign of the third torque the same as the sign of the third torque.

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