JP2008179277A - Traveling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the vibration of a vehicle without separately installing any sensor for detecting vibration with respect to the vertical direction of the vehicle. <P>SOLUTION: This vehicle 1 is provided with a traveling device 100. The traveling device 100 is provided with a motor MG in each wheel W. Then, the motor MG applies a driving/braking force to reduce load fluctuation in the vertical direction of the vehicle 1 as compared with the present time to the wheel W based on a relation between the ground load fluctuation of the wheel W to be acquired based on the fluctuation of the revolving speed of the wheel W detected by a resolver Q and the driving/braking force of the wheel W and the load fluctuation in the vertical direction of the vehicle 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a traveling device that can suppress vibration in a vertical direction of a vehicle by changing a braking / driving force of a wheel.

  In a vehicle such as a passenger car or a truck, a wheel is attached to a vehicle body via a suspension device, and an impact input from the road surface via the wheel is absorbed by a spring provided in the suspension device and mitigated. The unsprung and unsprung vibrations of the suspension affect the riding comfort of the vehicle and the running performance of the vehicle. Patent Document 1 discloses a braking / driving force control device that makes a difference in driving force between front and rear wheels and suppresses vertical vibration of a vehicle body according to the vertical vibrations of a wheel detected using a sprung acceleration sensor and an unsprung acceleration sensor. Is disclosed.

JP 2006-109642 A

  However, the suspension device disclosed in Patent Document 1 requires a sensor for detecting up-and-down vibrations of the vehicle on and off the spring, resulting in an increase in the mass and cost of the vehicle. This invention is made in view of the above, Comprising: It aims at providing the traveling apparatus which can suppress the vibration of a vehicle, without providing the sensor for detecting the vibration with respect to the up-down direction of a vehicle separately. .

  In order to solve the above-described problems and achieve the object, a traveling device according to the present invention includes a wheel rotation speed detection unit that detects a rotation speed of a wheel that supports a vehicle via a suspension device, and a rotation speed of the wheel. And the braking / driving force for reducing the load variation from the present time based on the relationship between the wheel ground load variation obtained based on the variation of the wheel and the braking / driving force of the wheel and the load variation in the vertical direction of the vehicle. And vibration suppression means applied to the wheel.

  This traveling device suppresses the vibration of the vehicle in the vertical direction by the vertical component of the reaction force of the braking / driving force. At this time, the vertical component of the braking / driving reaction force is obtained based on the relationship between the wheel ground load variation obtained based on the wheel rotational speed variation and the wheel braking / driving force, and the load variation in the vertical direction of the vehicle. The wheel is driven by the braking / driving force obtained from the vertical component. With such a configuration, the vibration of the vehicle can be suppressed without separately providing a sensor for detecting the vibration in the vertical direction of the vehicle.

  As a preferred aspect of the traveling device according to the present invention, the vibration suppressing means is based on the ground load variation of the wheel and the load variation in the vertical direction of the sprung structure of the suspension device in the vertical direction of the sprung structure. It is desirable to give the wheel a braking / driving force that makes the load fluctuation smaller than the present time.

  As a preferred aspect of the traveling device according to the present invention, the vibration suppressing means is based on the ground load variation of the wheel and the load variation in the vertical direction of the unsprung structure of the suspension device in the vertical direction of the unsprung structure. It is desirable to give the wheel a braking / driving force that makes the load fluctuation smaller than the present time.

  As a preferred aspect of the traveling device according to the present invention, the vibration suppressing means is obtained from the ground contact load variation of the wheel and the load variation in the vertical direction of the sprung structure of the suspension device. The unsprung structure obtained on the basis of the first braking / driving force that makes the load fluctuation in the vertical direction smaller than the present time, the ground load fluctuation of the wheel and the load fluctuation in the vertical direction of the unsprung structure of the suspension device It is desirable to apply to the wheels a braking / driving force obtained by adding a second braking / driving force that makes the load fluctuation in the vertical direction of the object smaller than the current time.

  As a preferred aspect of the traveling device according to the present invention, it is desirable that the vibration suppressing means is a power generation means for the wheel.

  The traveling device according to the present invention can suppress the vibration of the vehicle without separately providing a sensor for detecting the vibration in the vertical direction of the vehicle.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited by the best mode for carrying out the invention (hereinafter referred to as an embodiment). In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range.

  In the following, the case where the present invention is applied to a so-called electric vehicle using an electric motor as the power generation means will be described, but the application target of the present invention is not limited to this, based on fluctuations in the rotational speed of the wheel, The present invention can be applied as long as it includes vibration suppressing means for suppressing the vertical vibration of the wheel. The power generation means is not limited to an electric motor, and may be an internal combustion engine, or a so-called hybrid power generation means in which an internal combustion engine and an electric motor are combined. In the present invention, the number of wheels provided in the vehicle is not limited to four, and the present invention can also be applied to suppressing vibration of at least one of a sprung or unsprung state of a single wheel. Of the wheels provided in the vehicle, the number of drive wheels is not limited.

  In the present embodiment, the term “on a spring” refers to the upper side than the spring of the suspension device provided in the vehicle, and the term “under the spring” refers to the lower side than the spring of the suspension device provided in the vehicle. In addition, when referring to vibration on the spring, load fluctuation, etc., it means vibration in the vertical direction of the structure arranged on the spring of the suspension, load fluctuation, etc., and when referring to vibration below the spring, load fluctuation, etc., This refers to vibration in the vertical direction of a structure disposed under the spring, load fluctuation, and the like. Here, the vertical direction refers to a direction parallel to the direction of gravity when the vehicle 1 is horizontally disposed.

  FIG. 1 is a schematic diagram illustrating a configuration of a vehicle including a traveling device according to the present embodiment. This embodiment is characterized by the following points. That is, in a vehicle that supports a wheel via a suspension system, the vibration of the sprung structure in the vertical direction and the load fluctuation of the unsprung structure, that is, the vibration in the vertical direction, are caused by the reaction force (braking and braking). Suppressed by the vertical component of the reaction force. At this time, based on the relationship between the wheel ground load variation obtained based on the wheel rotational speed variation and the wheel braking / driving force, and the load variation in the vertical direction of the vehicle, The component is obtained, and the braking / driving force is obtained from this vertical component.

  A vehicle 1 shown in FIG. 1 includes a traveling device 100 that uses only an electric motor as power generation means. The travel device 100 includes a left front motor 10L, a right front motor 10R, a left rear motor 11L, and a right rear motor 11R as power generation means. The left front motor 10L drives the left front wheel 2L, the right front motor 10R drives the right front wheel 2R, the left rear motor 11L drives the left rear wheel 3L, and the right rear motor 11R drives the right rear wheel 3R. Thus, this traveling device 100 is an all-wheel drive type in which all wheels are drive wheels. The left front motor 10L, the right front motor 10R, the left rear motor 11L, and the right rear motor 11R are so-called in-wheel types that are arranged in the wheels of the left front wheel 2L, the right front wheel 2R, the left rear wheel 3L, and the right rear wheel 3R. It becomes the composition of.

  In this embodiment, the left front motor 10L, the right front motor 10R, the left rear motor 11L, and the right rear motor 11R, which are power generation means, are vibrations of the vehicle 1, that is, vibrations of a sprung structure of the vehicle 1 and unsprung structures. It also functions as a vibration suppressing means for suppressing the vibrations. Thus, by using the left front motor 10L, the right front motor 10R, the left rear motor 11L, and the right rear motor 11R, which are power generation means, as the vibration suppression means, it is not necessary to separately provide the vibration suppression means. It is advantageous for downsizing and cost reduction.

  In the following description, when the four motors are not distinguished, they are simply referred to as the motor MG, and when the four wheels are not distinguished, they are simply referred to as the wheels W. When attention is paid to the front and rear of the vehicle 1 among the four wheels, the front wheels 2 and the rear wheel 3 are called. The same). Here, the left-right distinction is based on the direction in which the vehicle 1 (or the traveling device 100) moves forward (the direction of the arrow X in FIG. 1). That is, “left” means the left side in the direction in which the vehicle 1 (or travel device 100) moves forward, and “right” means the right side in the direction in which the vehicle 1 (or travel device 100) moves forward. Say.

  In the present embodiment, the electric motor MG and the wheels W are directly connected. That is, the rotor of the electric motor MG is connected to the wheels W via the output shaft of the electric motor MG. In the present embodiment, the left front motor 10L, the right front motor 10R, the left rear motor 11L, and the right rear motor 11R are independently controlled by an ECU (Engine Control Unit) 50, respectively. As a result, the driving forces of the left front wheel 2L, the right front wheel 2R, the left rear wheel 3L, and the right rear wheel 3R are independently controlled. The distribution ratio among the driving force of the left front wheel 2L, the driving force of the right front wheel 2R, the driving force of the left rear wheel 3L, and the driving force of the right rear wheel 3R is changed by the ECU 50 as necessary. As a result, it is possible to provide a difference in rotational speed between the inner and outer wheels and the front and rear wheels during turning, or to perform traction control.

  Note that a speed reduction mechanism may be provided between the electric motor MG and the wheels W, and the rotational speed of the electric motor MG may be reduced and transmitted to the left and right wheels W. In general, when the electric motor is downsized, the torque decreases. However, by providing a speed reduction mechanism, the electric motor torque can be increased and transmitted to the wheels W. As a result, the electric motor MG mounted on the traveling device 100 can be reduced in size.

  The left front motor 10L, the right front motor 10R, the left rear motor 11L, and the right rear motor 11R include a left front motor resolver 40L, a right front motor resolver 40R, a left rear motor resolver 41L, and a right rear motor resolver 41R. The rotation speed is detected. The outputs of the resolver 40L for the left front motor, the resolver 40R for the right front motor, the resolver 41L for the left rear motor, and the resolver 41R for the right rear motor are taken into the ECU 8 for the motor, and the left front motor 10L, the right front motor 10R, the left rear motor 11L, Used for controlling the right rear motor 11R. Here, when the four wheels are not distinguished, they are simply referred to as resolver Q.

  As described above, the resolver Q detects the rotation speed and rotation speed of the electric motor MG in the present embodiment. In the present embodiment, since the electric motor MG and the wheel W are directly connected, the rotational speed of the wheel W can be detected by the resolver Q detecting the rotational speed of the electric motor MG. That is, the resolver Q functions as a wheel rotation speed detection unit. In addition, what is necessary is just to obtain | require the rotational speed of the wheel W from the resolver Q in consideration of the reduction ratio of a deceleration mechanism, when driving the wheel W with the electric motor MG via a deceleration mechanism.

  In this embodiment, since the rotational speed of the wheel W can be obtained by the resolver Q, it is not necessary to separately provide a sensor for detecting the rotational speed of the wheel W. As a result, the degree of freedom of the arrangement of the devices such as the electric motor MG and the braking device is improved, and the manufacturing cost of the traveling device 100 and the vehicle 1 can be reduced. In addition, space saving can be achieved. Depending on the configuration of the power generation means provided in traveling device 100, a sensor for detecting the rotational speed of wheel W may be provided separately.

  The left front motor 10L, the right front motor 10R, the left rear motor 11L, and the right rear motor 11R are connected to the motor control circuit 6. A vehicle-mounted power source 7 such as a nickel-hydrogen battery or a lead-acid battery mounted on the vehicle 1 shown in FIG. 1 is connected to the motor control circuit 6. Electric power for driving the electric motor 10R, the left rear motor 11L, and the right rear motor 11R is supplied. The electric motor control circuit 6 includes three inverter circuits for generating three-phase currents of W, V, and U. In the inverter circuit, the motor ECU 8 is controlled by the motor ECU 8 based on a command from the ECU 50. As a result, the left front motor 10L, the right front motor 10R, the left rear motor 11L, and the right rear motor 11R are driven and controlled.

  In the present embodiment, the outputs of the left front motor 10L, the right front motor 10R, the left rear motor 11L, and the right rear motor 11R are controlled by the opening of the accelerator 5 detected by the accelerator opening sensor 42. As a result, the traveling device 100 total driving forces F_all are controlled. In the present embodiment, one electric motor is controlled by one inverter circuit. The traveling device 100 includes four motors, that is, a left front motor 10L, a right front motor 10R, a left rear motor 11L, and a right rear motor 11R. In order to control these, the motor control circuit 6 includes four inverter circuits. Is provided.

  When the electric motor MG is used as power generation means of the traveling device 100, electric power from the in-vehicle power supply 7 is supplied via the electric motor control circuit 6. The torque generated by the electric motor MG is applied to the wheels W as the driving force of the wheels W. For example, when the vehicle 1 is decelerated, the electric motor MG functions as a generator to perform regenerative power generation, and the energy recovered thereby is stored in the in-vehicle power source 7. This is realized by the ECU 50 controlling the motor control circuit 6 based on a brake signal detected by the brake sensor 46 or a signal such as an accelerator off. In this case, the regenerative torque generated by the electric motor MG is applied to the wheel W as a braking force of the wheel W. As described above, the electric motor MG serving as the power generation means applies the driving force and the braking force to the wheels W.

  The ECU 50 controls the driving force of the traveling device 100 according to this embodiment, and regenerates electric power by the electric motor MG during braking. Further, as will be described later, the ECU 50 is provided with a vibration suppression control device 30 and executes vibration suppression control according to the present embodiment. In the present embodiment, the vibration suppression control device 30 is realized as a function of the ECU 50. The ECU 50 is connected to the communication line 9. The traveling device 100 includes a resolver Q, an accelerator opening sensor 42, a yaw sensor 43, a vehicle speed sensor 44, a steering angle sensor 45, a brake sensor 46, and the like that are also connected to the communication line 9. Acquire information necessary for control.

  FIG. 2 is an explanatory diagram illustrating a configuration example of the suspension device provided in the vehicle according to the present embodiment. As shown in FIG. 2, the electric motor MG (the left front motor 10L, the right front motor 10R, the left rear motor 11L, and the right rear motor 11R shown in FIG. 1) is attached to the suspension device 1S. Thus, the electric motor MG is attached to the vehicle main body 1B of the vehicle 1 via the suspension device 1S and supported by the vehicle 1 by the suspension device 1S.

  As shown in FIG. 2, in the present embodiment, the suspension device 1S uses a so-called strut type. An upper mount 20U is provided at one end of the damper 20 which is a damping force generating means, and the damper 20 is attached to the vehicle body 1B through this. An electric motor fixing bracket 20 </ b> B is provided at the other end of the damper 20. The electric motor fixing bracket 20B is attached to an electric motor side bracket MGb provided in the main body of the electric motor MG, and fixes the damper 20 and the electric motor MG. Here, a resolver Q is attached to the drive shaft (motor drive shaft) MGs of the electric motor MG as rotation angle detection means for knowing the rotation angle of the electric motor drive shaft MGs. By processing the signal detected by the resolver Q, the rotational speed of the electric motor MG can be known.

  A pivot portion MGp is provided at a position symmetrical to the electric motor side bracket MGb with respect to the electric motor drive shaft MGs. The pivot portion MGp is combined with the pivot receiver 28 of the transverse link (lower arm) 22 and is pin-coupled. The transverse link 22 is attached to the vehicle main body 1 </ b> B by the vehicle attachment portion 27. Then, the electric motor MG moves in the vertical direction (the X direction in FIG. 2, the same applies hereinafter), thereby swinging about the swing axis Zsf of the vehicle attachment portion 27. Here, the vertical direction is a direction parallel to the direction of gravity action.

  A brake rotor 15 and a wheel 13 are attached to the electric motor drive shaft MGs. And the tire 14 is attached to the wheel 13, and it becomes the wheel W. By input from the road surface to the wheel W, the wheel 13 moves in the vertical direction. Since the wheel 13 is attached to the motor drive shaft MGs, the wheel 13 operates in the vertical direction, and the motor MG also operates in the vertical direction. The input to the vehicle main body 1B due to the electric motor MG operating in the vertical direction is absorbed by the spring 20S and the damper 20 of the suspension device 1S.

  Since the motor MG and the transverse link 22 are pin-connected by the pivot portion MGp and the pivot receiver 28, the transverse link 22 can swing about the swing axis Zsf as the motor MG moves up and down. The electric motor MG is steered together with the wheel 13 and the tire 14 by the operation of the handle 4. At this time, the pivot portion MGp rotates while being supported by the pivot receiver 28.

  FIG. 3 is an explanatory diagram illustrating a configuration example of the vibration suppression control device according to the present embodiment. As shown in FIG. 3, the vibration suppression control device 30 is configured to be incorporated in the ECU 50. The ECU 50 includes a CPU (Central Processing Unit) 50p, a storage unit 50m, and input and output ports 55 and 56.

  In addition, separately from ECU50, the vibration suppression control apparatus 30 which concerns on this embodiment may be prepared, and this may be connected to ECU50. And in implement | achieving starting control of the internal combustion engine which concerns on this embodiment, you may comprise so that the said vibration suppression control apparatus 30 can utilize the control function with respect to the traveling apparatus 100 grade | etc., With which ECU50 is provided.

  The vibration suppression control device 30 includes a disturbance input estimation unit 31, a load fluctuation calculation unit 32, a vibration suppression braking / driving force calculation unit 33, and a vibration suppression torque calculation unit 34. These are the parts that execute the vibration suppression control according to the present embodiment. In the present embodiment, the vibration suppression control device 30 is configured as a part of the CPU 50p configuring the ECU 50. The CPU 50p is provided with an electric motor output control unit 50pe, which controls the output of the electric motor MG and the regeneration of electric power when the vehicle 1 travels, and based on the processing result of the vibration suppression control executed by the vibration suppression control device 30. To control the output (torque) of the electric motor MG. The CPU 50p is provided with a general control unit 50pc, and calculates information necessary for controlling the electric motor MG.

The CPU 50p and the storage unit 50m are connected via an input port 55 and an output port 56 via buses 54 _{1 to} 54 ₃ . Thereby, the disturbance input estimation unit 31, the load fluctuation calculation unit 32, the vibration suppression braking / driving force calculation unit 33, and the vibration suppression torque calculation unit 34 constituting the vibration suppression control device 30 exchange control data with each other, It is configured so that instructions can be issued to one side. Further, the vibration suppression control device 30 can acquire the operation control data of the traveling device 100 included in the ECU 50 and use this. Further, the vibration suppression control device 30 can cause the vibration suppression control according to the present embodiment to interrupt an operation control routine provided in advance in the ECU 50.

  The input port 55 is connected to the communication line 9. The communication line 9 is connected to an accelerator opening sensor 42, a yaw sensor 43, a vehicle speed sensor 44, a steering angle sensor 45, a brake sensor 46, and other sensors that acquire information necessary for controlling the traveling device 100. The CPU 50 p acquires signals output from these sensors via the communication line 9. Further, the CPU 50 p acquires the rotation speed of the electric motor MG from the resolver Q via the communication line 9. Thereby, CPU50p can acquire information required for driving control of traveling device 100, and vibration suppression control concerning this embodiment. The output port 56 is connected to the communication line 9. The vibration suppression control command for the electric motor MG (left front motor 10L, right front motor 10R, left rear motor 11L, right rear motor 11R) calculated by the CPU 50p is transmitted to the motor ECU 8 via the communication line 9. Thus, the electric motor MG can be controlled via the electric motor ECU 8.

  The storage unit 50m stores a computer program including a processing procedure of vibration suppression control according to the present embodiment, a control map, data used for vibration suppression control according to the present embodiment, and the like. Here, the storage unit 50m can be configured by a volatile memory such as a RAM (Random Access Memory), a nonvolatile memory such as a flash memory, or a combination thereof.

  The computer program may be capable of realizing the vibration suppression control processing procedure according to the present embodiment in combination with the computer program already recorded in the CPU 50p. In addition, the vibration suppression control device 30 uses a dedicated hardware instead of the computer program, and uses a disturbance input estimation unit 31, a load fluctuation calculation unit 32, a vibration suppression braking / driving force calculation unit 33, and a vibration suppression torque calculation unit. 34 may be realized.

  The motor ECU 8 connected to the communication line 9 includes an input port 8i, a CPU 8p, and a pre-driver 8d. The input port 8i is connected to the communication line 9, and the CPU 8p acquires the vibration suppression control signal command of the electric motor MG transmitted from the ECU 50 via the communication line 9 and the input port 8i. CPU8p calculates the value of the electric current supplied to the electric motor MG based on the acquired vibration suppression control command, that is, the current command value. Then, the CPU 8p outputs the calculated current command value to the pre-driver 8d, and drives and controls the electric motor MG via the pre-driver 8d and the electric motor control circuit 6 connected to the pre-driver 8d.

  Further, the CPU 8p detects the motor rotation speed and the drive current detected by the resolver Q (the left front motor resolver 40L, the right front motor resolver 40R, the left rear motor resolver 41L, the right rear motor resolver 41R) via the communication line 9. The drive current value of the electric motor MG detected by the detection circuit 47 is acquired. Then, the CPU 8p feedback-controls the electric motor MG so that the electric motor MG is driven according to the driving command and the vibration suppression control command of the electric motor MG transmitted from the ECU 50 based on the acquired electric motor rotation speed and driving current value. To do.

  The pre-driver 8d provided in the motor ECU 8 is for converting the current command value calculated by the CPU 8p into the duty command values W, V, U, Wb, Vb, Ub subjected to pulse width modulation. Here, the duty command values W, V, and U represent normal-phase three-phase signals, and the duty command values Wb, Vb, and Ub represent reverse-phase three-phase signals. The duty command values W, V, U, Wb, Vb, and Ub output from the pre-driver 8d are sent to an inverter circuit included in the motor control circuit 6, and the left front motor 10L, the right front motor 10R, the left rear motor 11L, and the right rear The motor 11R is subjected to vibration suppression control.

  FIG. 4 is a conceptual diagram for explaining the reaction force of braking / driving force and the vertical component of the reaction force of braking / driving force. FIG. 5 is a conceptual diagram showing a modeled vehicle. In the vibration suppression control according to the present embodiment, the fluctuation of the ground load of the wheel W is obtained by obtaining the fluctuation of the ground load of the wheel W and applying the vertical component of the reaction force of the braking / driving force (braking / driving reaction force). Is made smaller. For this purpose, the braking / driving force of the wheel W is controlled. First, the braking / driving reaction force will be described.

  The braking / driving reaction force due to the braking / driving force F_drive generated by the wheel W is F, and the vertical component of the braking / driving reaction force F is Freac. Here, the braking / driving reaction force F is a force having the same magnitude as the braking / driving force F_drive, and is a force by which the road surface GL pushes the wheel W in a direction opposite to the direction of the braking / driving force F_drive. In the present embodiment, the braking / driving force F_drive is a driving force that drives the wheel W to drive the vehicle 1 shown in FIG. 1 and a braking force that brakes the wheel W to brake the vehicle 1 shown in FIG. It is a concept that includes both. The braking force includes both braking by the above-described regenerative torque of the electric motor MG and braking force by the braking device (brake) of the wheels W.

  In FIG. 4, the instantaneous rotation center OR of the suspension device is OR, the distance between the instantaneous rotation center OR of the suspension device and the ground contact portion P where the wheel W contacts the road surface GL, and the straight line connecting OR and P to the road surface GL. The angle formed is α. The braking / driving reaction force component orthogonal to the straight line connecting OR and P is F × sin α. Therefore, the clockwise moment due to the braking / driving reaction force around the instantaneous rotation center OR of the suspension device is l × F × sin α. On the other hand, the counterclockwise moment due to the vertical component of braking / driving reaction force (braking / driving reaction force vertical component) Freac around the instantaneous rotation center OR of the suspension is Freac × l × cos α.

  Since the wheel W is constrained by the road surface GL and the wheel W does not rotate around the instantaneous rotation center OR of the suspension device, l × F × sin α = Freak × l × cos α. When this is solved for Freac and rearranged, the braking / driving reaction force vertical component Freac can be expressed by Expression (1).

  That is, the braking / driving reaction force vertical component Freac can be obtained by multiplying the braking / driving reaction force F by tan α. Here, since α is a value determined in advance by the design of the suspension device 1S, tan α is a constant, and the braking / driving reaction force vertical component Freac is a function of the braking / driving reaction force F. Next, vibration suppression control according to the present embodiment will be described.

  In the vehicle 1 that supports the wheel W via the suspension device 1S shown in FIG. 2, the vibration suppression control according to the present embodiment is the vibration of the sprung structure of the suspension device 1S and the load fluctuation in the vertical direction of the unsprung structure. That is, the vibration in the vertical direction is suppressed by the braking / driving reaction force vertical component Freac shown by the equation (1). At this time, the braking / driving reaction force vertical component Freac is obtained from the ground load variation of the wheel W obtained on the basis of the rotational speed variation of the wheel W and the braking / driving force of the wheel W. Then, by applying the braking / driving force obtained from the braking / driving reaction force vertical component Freac to the wheel W, the vibration of the sprung structure and the vibration in the vertical direction of the unsprung structure are suppressed.

  The relationship between the torque T for controlling and driving the wheel W by the electric motor MG as the power generation means and the fluctuation of the rotational speed ω of the wheel W, that is, the rotational acceleration (wheel rotational acceleration) ω ′ of the wheel W is expressed by the equation (2). It becomes like this. The wheel rotational acceleration ω ′ is a rotational angular acceleration and is a one-time differential value of the rotational speed ω of the wheel W. When the ground load M of the wheel W is obtained from the equation (2), the equation (3) is obtained. The ground load M of the wheel W obtained by the equation (3) is referred to as driving wheel load.

  When the static ground load (hereinafter referred to as wheel static load) of the wheel W is M0, and the deviation (referred to as ground load fluctuation) ΔM between the wheel static load M0 and the driving wheel load M obtained by the equation (3) is obtained, Equation (4) is obtained. The ground load variation ΔM represents a load input to the wheel W due to disturbance. That is, if there is no disturbance, the ground load variation ΔM does not occur, but the fact that the ground load variation ΔM has occurred is presumed that a disturbance has occurred.

  Here, J is the inertia of the wheel, and R is the dynamic load radius of the wheel W. Here, when the electric motor MG applies the torque T to the wheel W, a braking / driving force F_drive having a magnitude (T / R) obtained by dividing the torque T by the dynamic load radius R of the wheel W is generated in the wheel W. Therefore, the ground load variation ΔM is obtained based on the variation of the rotational speed ω of the wheel W, that is, the wheel rotational acceleration ω ′ and the braking / driving force F_drive of the wheel W.

  Next, from the two-degree-of-freedom model (see FIG. 5) that targets a single wheel W among the plurality of wheels W included in the vehicle 1, the load fluctuation of the vehicle 1 with respect to the load input due to the disturbance to the wheel W, Specifically, the load fluctuation (sprung load fluctuation) of the sprung structure 1BU and the load fluctuation (unsprung load fluctuation) of the unsprung structure 1BL with respect to the load input due to the disturbance to the wheel W are obtained. A load input due to a disturbance to the wheel W is represented by a ground load variation ΔM. The ground load variation ΔM has a vibration component, and a load input due to a disturbance to the wheel W also has a vibration component. Therefore, the load fluctuation of the vehicle 1 with respect to the load input due to the disturbance to the wheels W causes the vehicle 1 (the sprung structure 1BU or the unsprung structure 1BL) to vibrate.

  Here, the sprung structure 1BU is a structure that exists above the spring 20S of the suspension device 1S included in the vehicle 1 shown in FIG. 5, and is, for example, in the vehicle main body 1B or the vehicle main body 1B shown in FIG. Such as a structure. The unsprung structure 1BL is a structure that exists below the spring 20S of the suspension device 1S included in the vehicle 1 shown in FIG. 5, and is, for example, the electric motor MG, the wheel W, or the like shown in FIG.

  In a state where the unsprung mass M2 is vibrated by the ground load variation ΔM due to disturbance from the road surface GL, the mass of the unsprung structure 1BU (sprung mass) M1 and the mass of the unsprung structure 1BL (unsprung mass) The equation of motion for M2 is as shown in equation (5). Here, k1 in the equation (5) is a spring constant of the spring 20S provided in the suspension device 1S shown in FIG. 5, and c1 is a damping coefficient of the damper 20 provided in the suspension device 1S shown in FIG.

  When formula (5) is arranged with respect to displacement (sprung mass displacement) X1 of unsprung structural material amount M1 and displacement (unsprung mass displacement) X2 of unsprung structural material amount M1 with respect to ground load variation ΔM, formula (6) (7). Note that s is a Laplace operator (the same applies hereinafter).

When the unsprung load variation Spring (s) and the unsprung load variation Unsprung (s) are obtained from the equations (6) and (7), the equations (8) and (9) are obtained. Thus, the relationship between the ground load variation ΔM and the sprung load variation Sprun (s) is obtained in the equation (8), and the relationship between the ground load variation ΔM and the unsprung load variation Unsprung (s) is obtained in the equation (9). It is done. Here, the unsprung load variation is M1 × d ² X1 / dt ² , and the unsprung load variation is M1 × d ² X2 / dt ² .

  Next, from the equations (8) and (9), the unsprung load variation Sprun (s) and the vertical component of the driving reaction force F (drive reaction force vertical component) are balanced, and the unsprung load variation Unsprung (s). The first braking / driving reaction force vertical component Freac_U and the second braking / driving reaction force vertical component Freac_L are obtained so that a balance between the torque and the driving reaction force vertical component is established. The first braking / driving reaction force vertical component Freac_U with respect to the unsprung load variation Sprun (s) is expressed by equation (10), and the second braking / driving reaction force vertical component Freac_L with respect to the unsprung load variation Unsprung (s) is expressed by equation (11). It is. Here, the first braking / driving reaction force vertical component Freac_U is a force that suppresses the unsprung load variation Spring (s), and the second braking / driving reaction force vertical component Freac_L is the unsprung load variation Unsprung (s). It is the power that suppresses.

  In the present embodiment, vibration of the sprung structure 1BU of the vehicle 1 can be suppressed. In this case, the first braking / driving reaction force vertical component Freac_U is applied so as to cancel the vibration of the sprung structure 1BU of the vehicle 1. Therefore, by changing the torque generated by the electric motor MG, the first braking / driving reaction force vertical component Freac_U is changed to suppress the vibration of the sprung structure 1BU of the vehicle 1.

  The first braking / driving reaction force vertical component Freac_U given by Expression (10) is a driving reaction force vertical component necessary for suppressing the vibration of the sprung structure 1BU of the vehicle 1. Therefore, in order to convert the first braking / driving reaction force vertical component Freac_U into the braking / driving force (first braking / driving force) F_drive1 of the wheel W, as shown in Expression (12), the instantaneous rotation of the suspension device 1S is performed. Multiply the tangent value of the center OR by the first braking / driving reaction force vertical component Freac_U. The torque (first vibration suppression torque) Tdv_U generated by the electric motor MG is obtained by multiplying the first braking / driving force F_drive1 by the dynamic load radius R of the wheel W.

  When the electric motor MG generates the first vibration suppression torque Tdv_U obtained from Expression (12), the first braking / driving force F_drive1 is applied to the wheel W, and the first given by Expression (10). A braking / driving reaction force vertical component Freac_U is generated. Thereby, the vibration of the sprung structure 1BU of the vehicle 1 is suppressed more than the current time.

  Moreover, in this embodiment, the vibration of the unsprung structure 1BL of the vehicle 1 can be suppressed. In this case, the second braking / driving reaction force vertical component Freac_L is applied so as to cancel the vibration of the unsprung structure 1BL of the vehicle 1. Therefore, by changing the torque generated by the electric motor MG, the second braking / driving reaction force vertical component Freac_L is changed, and the vibration of the unsprung structure 1BL of the vehicle 1 is suppressed.

  Expression (11) is a driving reaction force vertical component necessary for suppressing vibration of the unsprung structure 1BL of the vehicle 1. Therefore, in order to convert the second braking / driving reaction force vertical component Freac_L into the braking / driving force (second braking / driving force) F_drive2 of the wheel W, as shown in Expression (13), the instantaneous rotation center of the suspension device 1S The tangent value of OR is multiplied by the second braking / driving reaction force vertical component Freac_L. The torque (second vibration suppression torque) Tdv_L generated by the electric motor MG is obtained by multiplying the second braking / driving force F_drive2 by the dynamic load radius R of the wheel W.

  When the electric motor MG generates the second vibration suppression torque Tdv_L obtained from the equation (13), the second braking / driving force F_drive2 is given to the wheel W, and the second given by the equation (11) is given. A braking / driving reaction force vertical component Freac_L is generated. Thereby, the vibration of the unsprung structure 1BL of the vehicle 1 is suppressed more than the current time.

  In the present embodiment, vibrations of the sprung structure 1BU and the unsprung structure 1BL of the vehicle 1 can be simultaneously suppressed. In this case, the vertical component of the driving reaction force F is applied so as to cancel the vibration of the sprung structure 1BU and the unsprung structure 1BL of the vehicle 1. At this time, by changing the torque generated by the electric motor MG, the first braking / driving reaction force vertical component Freac_U and the second braking / driving reaction force vertical component Freac_L are changed, and the sprung structure 1BU of the vehicle 1 is changed. And the vibration of the unsprung structure 1BL is suppressed simultaneously.

  In general, the resonance frequency of the sprung structure 1BU is 1 Hz to 2 Hz, but the resonance frequency of the unsprung structure 1BL is 10 Hz to 14 Hz. Therefore, the fluctuation of the sprung load obtained from the expressions (10) and (11) Sprung (s) and unsprung load variation Unsprung (s) have different frequency bands. For this reason, in order to obtain the driving reaction force vertical component (vehicle vibration suppression vertical component) Freac_B necessary for suppressing the vibration of the sprung structure 1BU and the unsprung structure 1BL of the vehicle 1, the sprung load fluctuation Sprun ( s) is added to the first braking / driving reaction force vertical component Freac_U and the second braking / driving reaction force vertical component Freac_L to suppress unsprung load fluctuation Unsprung (s) (formula (14) )reference).

  In order to convert the vehicle vibration suppression vertical component Freac_B in Expression (14) into the braking / driving force (vehicle vibration suppression braking / driving force) F_drive_B of the wheel W, as shown in Expression (15), the instantaneous rotation center OR of the suspension device 1S is calculated. Is multiplied by the vehicle vibration suppression vertical component Freac_B. The torque Tdv generated by the electric motor MG is obtained by multiplying the vehicle vibration suppression braking / driving force F_drive_B by the dynamic load radius R of the wheel W.

  When the electric motor MG generates the vibration suppression torque Tdv obtained from Expression (15), vehicle vibration suppression braking / driving force F_drive_B is applied to the wheels W, and the vehicle vibration suppression vertical component Freac_B given by Expression (14). Will occur. Thereby, the vibration of the sprung structure 1BU and the unsprung structure 1BL of the vehicle 1 is suppressed more than the current time.

  Here, the vehicle vibration suppression braking / driving force F_drive_B of Expression (15) is a value obtained by adding the first braking / driving force F_drive1 and the second braking / driving force F_drive2. Further, the vibration suppression torque Tdv obtained from the equation (15) is obtained by adding the first vibration suppression torque Tdv_U shown in the equation (12) and the second vibration suppression torque Tdv_U shown in the equation (13). . Next, a procedure example of vibration suppression control according to this embodiment will be described. The traveling device 100 is controlled based on the vibration suppression control according to the present embodiment. Further, the vibration suppression control according to the present embodiment can be realized by the vibration suppression control device 30 shown in FIG.

  FIG. 6 is a flowchart showing a procedure of vibration suppression control according to the present embodiment. In executing the vibration suppression control according to the present embodiment, in step S101, the disturbance input estimation unit 31 of the vibration suppression control device 30 includes the left front wheel 2L, the right front wheel 2R, and the left rear wheel 3L of the traveling device 100 included in the vehicle 1. The wheel rotational accelerations ω′_fl, ω′_fr, ω′_rl, and ω′_rr of the right rear wheel 3R are obtained. Here, the wheel rotation acceleration of the left front wheel 2L (left front wheel rotation acceleration) is ω'_fl, the wheel rotation acceleration of the right front wheel 2R (right front wheel rotation acceleration) is ω'_fr, and the wheel rotation acceleration of the left rear wheel 3L (left rear). Wheel rotational acceleration) is ω′_rl, and wheel rotational acceleration of the right rear wheel 3R (right rear wheel rotational acceleration) is ω′_rr.

  The wheel rotation acceleration is calculated by the disturbance input estimation unit 31 from the left front motor resolver 40L, the right front motor resolver 40R, the left rear motor resolver 41L, the right rear motor resolver 41R, the rotational speed ω_fl of the left front wheel 2L, and the right front wheel 2R. The rotational speed ω_fr, the left rear wheel 3L rotational speed ω_rl, and the right rear wheel 3R rotational speed ω_rr are acquired and obtained by differentiating them. After obtaining the left front wheel rotational acceleration ω′_fl, the right front wheel rotational acceleration ω′_fr, the left rear wheel rotational acceleration ω′_rl, and the right rear wheel rotational acceleration ω′_rr, in step S102, the disturbance input estimating unit calculates the equation (3 ), The ground load fluctuations ΔM_fl, ΔM_fr, ΔM_rl, ΔM_rr of the left front wheel 2L, the right front wheel 2R, the left rear wheel 3L, and the right rear wheel 3R are obtained based on the equation (4).

  In step S103, the load fluctuation calculating unit 32 of the vibration suppression control device 30 calculates the ground load fluctuations ΔM_fl, ΔM_fr, ΔM_rl, ΔM_rr of the left front wheel 2L, the right front wheel 2R, the left rear wheel 3L, and the right rear wheel 3R to the left front wheel. 2L, the right front wheel 2R, the left rear wheel 3L, and the right rear wheel 3R are given to formulas (8) and (9). As a result, the load variation calculation unit 32 obtains the sprung load variation Sprun (s) and the unsprung load variation Unsprung (s).

  Then, in step S104, the vibration suppression braking / driving force calculation unit 33 of the vibration suppression control device 30 creates equations (10) created for the left front wheel 2L, the right front wheel 2R, the left rear wheel 3L, and the right rear wheel 3R, respectively. The unsprung load variation Spring (s) and unsprung load variation Unsprung (s) obtained in step S103 are given to the equation (11). Accordingly, the vibration suppression braking / driving force calculation unit 33 suppresses the first braking / driving reaction force vertical component Freac_U that suppresses the sprung load fluctuation Sprung (s) and the second spring suppression load fluctuation Unsprung (s). The braking / driving reaction force vertical component Freac_L can be obtained for each of the left front wheel 2L, the right front wheel 2R, the left rear wheel 3L, and the right rear wheel 3R.

  In step S105, the vibration suppression braking / driving force calculation unit 33 calculates the first braking / driving reaction force vertical component Freac_U and the unsprung load variation Unsprung (s) that suppress the sprung load variation Sprung (s) obtained in step S104. The second braking / driving reaction force vertical component Freac_L to be suppressed is given to Expression (14) to obtain the vehicle vibration suppression vertical component Freac_B.

  In step S106, the vibration suppression braking / driving force calculation unit 33 gives the vehicle vibration suppression vertical component Freac_B obtained in step S105 to the equation (15), and the vibrations of the sprung structure 1BU and the unsprung structure 1BL of the vehicle 1 are calculated. A vehicle vibration suppression braking / driving force F_drive_B necessary for suppression is obtained.

  The vibration suppression torque calculator 34 of the vibration suppression control device 30 calculates the vibration suppression torque Tdv from the vehicle vibration suppression braking / driving force F_drive_B determined in step S106. The electric motor MG applies the vibration suppression torque Tdv to the wheel W to suppress the vibration of the sprung structure 1BU and the unsprung structure 1BL of the vehicle 1. The vehicle vibration suppression vertical component Freac_B and the vibration suppression torque Tdv are obtained for each of the left front wheel 2L, the right front wheel 2R, the left rear wheel 3L, and the right rear wheel 3R.

  When the vibration suppression suppression torque Tdv is obtained by the above procedure, in step S107, the motor output control unit 50pe of the ECU 50 determines the vibration suppression torques Tdv_fl, Tdv_fr, Tdv_rl, and Tdv_rr for each motor obtained in step S106, respectively. The current command value for each motor is calculated so that 10L, the right front motor 10R, the left rear motor 11L, and the right rear motor 11R are generated. In step S108, the motor ECU 8 controls the left front motor 10L, the right front motor 10R, the left rear motor 11L, and the right rear motor 11R based on the calculation result of the motor output control unit 50pe. Thereby, vibration of the sprung structure 1BU and the unsprung structure 1BL can be suppressed.

  In the above procedure, when the first and second braking / driving reaction force vertical components Freac_U and Freac_L are changed to suppress the vibration of the sprung structure 1BU and the unsprung structure 1BL of the vehicle 1, the front left motor 10L, the front right The torque of the motor 10R, the left rear motor 11L, and the right rear motor 11R is controlled. The torque control of each electric motor includes both power running torque control and regenerative torque control. In order to change the first and second braking / driving reaction force vertical components Freac_U and Freac_L, the braking force of the braking device that brakes the left front wheel 2L, the right front wheel 2R, the left rear wheel 3L, and the right rear wheel 3R, respectively. May be controlled.

  In the above procedure, the method of suppressing the vibration of the sprung structure 1BU and the unsprung structure 1BL of the vehicle 1 has been described. However, the vibration of the sprung structure 1BU of the vehicle 1 or the vibration of the unsprung structure 1BL is described. Any one of them may be suppressed. When suppressing the vibration of the sprung structure 1BU, the expression (12) is used, and when suppressing the vibration of the sprung structure 1BU, the expression (13) is used. Thus, this embodiment can suppress at least one of the vibration of the sprung structure 1BU of the vehicle 1 or the vibration of the unsprung structure 1BL.

  As described above, in the present embodiment, the vibration of the sprung structure of the vehicle that supports the wheel via the suspension device and the vibration of the unsprung structure are suppressed by the vertical component of the braking / driving reaction force. At this time, using the wheel ground load fluctuation obtained based on the wheel rotational speed fluctuation and the wheel braking / driving force as disturbance input, the ground contact is determined based on the relationship between the ground load fluctuation and the load fluctuation in the vertical direction of the vehicle. A vertical component of the braking / driving reaction force that suppresses the load fluctuation is obtained, and the braking / driving force is obtained from the vertical component. Accordingly, the vibration of the vehicle (at least one of the sprung structure and the unsprung structure) can be suppressed with a simple configuration without separately providing a sensor for detecting vibration in the vertical direction of the vehicle.

  As described above, the vibration suppression control device according to the present invention is useful for suppressing vehicle vibration, and is particularly suitable for suppressing vehicle vibration with a simple configuration.

It is the schematic which shows the structure of a vehicle provided with the traveling apparatus which concerns on this embodiment. It is explanatory drawing which shows the structural example of the suspension apparatus with which the vehicle which concerns on this embodiment is provided. It is explanatory drawing which shows the structural example of the vibration suppression control apparatus which concerns on this embodiment. It is a conceptual diagram explaining the vertical component of the reaction force of braking / driving force and the reaction force of braking / driving force. It is a conceptual diagram which shows the modeled vehicle. It is a flowchart which shows the procedure of the vibration suppression control which concerns on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 1B Vehicle main body 1BL Unsprung structure 1BU Sprung structure 1S Suspension device 2L Left front wheel 2R Right front wheel 3L Left rear wheel 3R Right rear wheel 6 Motor control circuit 7 In-vehicle power supply 8 Motor ECU
10L Left front motor 10R Right front motor 11L Left rear motor 11R Right rear motor 20 Damper 30 Vibration suppression control device 31 Disturbance input estimation unit 32 Load fluctuation calculation unit 33 Vibration suppression braking / driving force calculation unit 34 Vibration suppression torque calculation unit 40L Resolver for left front motor 40R Resolver for right front motor 41L Resolver for left rear motor 41R Resolver for right rear motor 50 ECU
100 travel device

Claims (5)

Wheel rotation speed detection means for detecting the rotation speed of the wheel supporting the vehicle via the suspension device;
Based on the relationship between the wheel ground load variation obtained based on the wheel rotation speed variation and the braking / driving force of the wheel, and the load variation in the vertical direction of the vehicle, the load variation is made smaller than the present time. Vibration suppressing means for applying braking / driving force to the wheels;
A traveling device comprising: The vibration suppressing means is
Based on the ground load variation of the wheel and the load variation in the vertical direction of the sprung structure of the suspension system, a braking / driving force is applied to the wheel that makes the load variation in the vertical direction of the sprung structure smaller than the present time. The traveling device according to claim 1. The vibration suppressing means is
Based on the ground load variation of the wheel and the load variation in the vertical direction of the unsprung structure of the suspension system, a braking / driving force is applied to the wheel that makes the load variation in the vertical direction of the unsprung structure smaller than the present time. The traveling device according to claim 1. The vibration suppressing means is
A first braking / driving force that is obtained on the basis of the ground load variation of the wheel and the load variation in the vertical direction of the sprung structure of the suspension device, and that makes the load variation in the vertical direction of the sprung structure smaller than the present time. When,
The second braking / driving force that is obtained based on the ground contact load variation of the wheel and the load variation in the vertical direction of the unsprung structure of the suspension device and that makes the load variation in the vertical direction of the unsprung structure smaller than the present time. The traveling device according to claim 1, wherein a braking / driving force obtained by adding to the wheel is applied to the wheel.   The travel device according to claim 1, wherein the vibration suppression unit is a power generation unit for the wheel.

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