JP2016116293A - Vibration damping control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration damping control device for effectively damping vibration above a spring while effectively preventing overcharge of a battery even when the vibration above the spring includes a high frequency component.SOLUTION: A vibration damping control device 10 for a vehicle includes: a battery 34; an electric motor 18 for applying driving force to front wheels 28FL, 28FR by using electricity from the battery; and a control device 40 for calculating target vibration damping torque Tdt for vibration damping above a spring and controlling the electric motor and a regenerative braking device so that vibration damping torque generated by driving torque and regenerative braking torque of the electric motor becomes the target vibration damping torque. The electric motor, an inverter 32 and the control device function as the regenerative braking device for charging the battery by using electricity generated by applying braking force to the right and left front wheels through regenerative braking. When the charge amount of the battery is a reference value or larger and a sum of the driving torque of the electric motor for traveling the vehicle and the target vibration damping torque is braking torque, the target vibration damping torque is corrected to a value Tdtf after low-pass filter processing.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vibration suppression control device for a vehicle, and more particularly to a vibration suppression control device that suppresses vibration on a spring by controlling a braking / driving force of a wheel in a vehicle in which regenerative braking is performed.

  When the braking / driving force of the wheel changes, the change of the braking / driving force of the wheel is transmitted to the spring via the suspension, and thereby a vertical force acts on the spring. Therefore, when pitching vibration or bounce vibration on the spring is generated as the vehicle travels, the braking / driving force of the wheel is positively changed, and the vertical vibration generated thereby is used to control the vibration on the spring. A vibration suppression control device is known.

  In this type of vibration suppression control device, the vibration on the spring is estimated based on the wheel speed or the like, and the target vibration suppression torque of the vehicle drive source for suppressing the estimated vibration on the spring is calculated. The output of the vehicle drive source is controlled so that a damping torque corresponding to the vibration torque is generated.

  Since the vibration on the spring includes a high frequency component, the braking / driving torque of the vehicle needs to be controlled with good responsiveness. Therefore, the control of the damping torque based on the target damping torque is achieved by controlling the output of the electric motor that constitutes at least a part of the driving source of the vehicle in a hybrid system equipped vehicle, an electric vehicle, a fuel cell vehicle, and the like. The For example, in Patent Document 1 below, in an in-wheel motor type electric vehicle, the output of a motor incorporated in each wheel is controlled, so that the damping torque is controlled to become the target damping torque. An example of a vibration control device is described.

JP 2009-173089 A

[Problems to be Solved by the Invention]
In a vehicle in which the electric motor constitutes at least a part of the driving source of the vehicle, regenerative braking is performed by causing the electric motor to function as a regenerative generator for the purpose of improving fuel consumption. In regenerative braking, a regenerative braking force is applied to the wheels, and the battery is charged with the generated electricity. Therefore, the battery is charged every time regenerative braking is performed.

  However, since the charge capacity of the battery is finite, when the charge amount of the battery exceeds a reference value, charging by regenerative braking is limited, thereby preventing overcharging of the battery. That is, when the charge amount of the battery is equal to or greater than the reference value, when the target torque of the motor is the braking torque and the target torque is larger than the limit reference value for limiting charging, the target torque is The size is limited so as not to be larger than the limit reference value.

  As will be described in detail later, the electric power that is generated and charged in the battery when damping by regenerative braking is performed not only increases as the damping torque increases, but also the frequency of the damping torque increases. It gets bigger. The vibration on the spring includes a high-frequency component, and the vibration suppression torque also includes a high-frequency component corresponding to this. In comparison, regenerative braking must be limited.

  For this reason, the limit reference value must be set to a value that is smaller than the limit reference value that is appropriate when the damping torque does not include a high-frequency component. Therefore, since the magnitude of the target torque when it is a braking torque is limited by a strict limit reference value, the damping torque is insufficient due to the limitation of the braking torque, and the vibration on the spring is effective. In some cases, this is not done.

The present invention has been made in view of the above-described problems in a conventional vibration damping control device that performs vibration damping control by controlling braking / driving torque of an electric motor in a vehicle in which regenerative braking is performed. The main problem of the present invention is to suppress vibration on the spring as effectively as possible while effectively preventing overcharge of the battery even when the vibration on the spring includes a high-frequency component. .
[Means for Solving the Problems and Effects of the Invention]

  According to the present invention, a battery that can be charged and discharged, an electric motor that applies a driving torque to a wheel by generating driving torque using electricity from the battery, and an electric motor are provided. A regenerative braking device that functions as a regenerative generator to generate a regenerative braking torque to apply braking force to the wheels and charges the battery with the generated electricity, and to suppress vibrations on the spring while the vehicle is running Target driving torque of the motor for driving the vehicle so that the actual damping torque generated by the driving torque and regenerative braking torque of the motor becomes the target damping torque. There is provided a vehicle vibration damping control device including control means for controlling the electric motor and the regenerative braking device based on a target torque that is the sum of the vibration damping torque.

  The vibration suppression control device includes a charge amount detection device that detects a charge amount of a battery, an index value calculation device that calculates an index value of a target torque indicating whether or not the target torque is a braking torque, and a target vibration suppression torque. And a filter device for low-pass filtering the indicated signal. The control means is configured to correct the target damping torque to a value indicated by the low-pass filter processed signal when the battery charge amount is equal to or greater than the reference value and the target torque index value is the braking torque. Yes. The “target torque index value” is used to determine whether or not the target torque is a braking torque, and is the sum of the target traveling drive torque and the value indicated by the low-pass filter processed signal, the target torque The signal indicating the target torque may be any value obtained by low-pass filtering.

  According to the above configuration, when the charge amount of the battery is equal to or larger than the reference value and the index value of the target torque is the braking torque, the target damping torque is corrected to a value from which the high frequency component is removed by the low-pass filter process. . Therefore, compared with the case where the target damping torque includes a high-frequency component, the power charged in the battery can be reduced, so that overcharging of the battery can be effectively prevented.

  In addition, since the amount of charge to the battery can be reduced compared to the case where the target damping torque is not subjected to low-pass filtering, the limit reference value for effectively preventing battery overcharge is large. May be. Therefore, in the situation where the target torque is the braking torque, the maximum value of the target torque that is not restricted by the restriction reference value can be increased. Therefore, compared with the case where the target damping torque is not subjected to low-pass filtering, the maximum value of the allowable target torque is increased in a situation where the target torque is a braking torque, and the necessity for damping is high. It is possible to effectively reduce the frequency sprung vibration.

  According to the above configuration, even if the charge amount of the battery is equal to or greater than the reference value, the target damping torque is not corrected to the low-pass filtered value when the target torque index value is the drive torque. Therefore, when the target value of the target torque is the driving torque, the damping torque can be controlled based on the target damping torque from which the high frequency component is not removed. Therefore, the vibration on the high-frequency spring can be effectively suppressed as compared with the case where the index value of the target torque is corrected to the value subjected to the low-pass filter process regardless of whether or not the braking torque is present.

  According to the present invention, in the above-described configuration, the control means performs the target control when the charge amount of the battery is equal to or larger than the reference value and the index value of the target torque is a braking torque larger than the processing reference value. The vibration torque may be configured to be corrected to a value indicated by the signal after the low pass filter process.

  According to the above configuration, when the magnitude of the target torque index value is equal to or smaller than the processing reference value, the target damping torque is not corrected to the value indicated by the signal after the low-pass filter processing, and thus the high frequency component is not removed. Therefore, the high-frequency sprung vibration can be effectively reduced as compared with the case where the target damping torque is corrected to the low-pass filtered signal regardless of the magnitude of the target torque index value. . Further, when the index value of the target torque is less than or equal to the processing reference value, the target torque does not become excessively large even if the target damping torque includes a high frequency component. Therefore, the electric power charged in the battery does not become excessive due to the high frequency component included in the target damping torque.

  According to the present invention, in the above configuration, the vibration suppression control device includes a restriction determination device that determines whether or not the supply of electric power due to battery discharge is to be restricted, and the control means includes discharging the battery. When the target torque index value is the drive torque, the target damping torque is corrected to the value indicated by the low-pass filter processed signal. It's okay.

  According to the above configuration, in a situation where the supply of power due to battery discharge should be limited, when the target torque index value is the drive torque, the target damping torque is removed from the high-frequency component by low-pass filtering. The value is corrected. Therefore, in a situation where the index value of the target torque is the drive torque, it is possible to effectively reduce the power supplied from the battery to the electric motor in order to reduce the high-frequency sprung vibration that is less necessary for damping.

  In each of the above configurations, the electric motor may be an electric motor that constitutes at least a part of a drive source of the vehicle in a hybrid system vehicle, an electric vehicle, and a fuel cell vehicle. The filter device may be a part of the control means.

  In each of the above configurations, the restriction determination device that determines whether or not the supply of power due to battery discharge should be restricted is whether or not the supply of power from the battery to the motor should be restricted. You may come to judge. For example, in the case of a vehicle provided with an eco mode switch that sets the vehicle travel mode to an eco mode that reduces vehicle energy consumption, power is supplied by discharging the battery when the eco mode switch is on. It may be determined that the situation should be restricted.

It is a schematic block diagram which shows one Embodiment of the vibration suppression control apparatus of the vehicle by this invention applied to the hybrid system mounting vehicle. It is a flowchart which shows the damping torque control routine in embodiment. It is a graph which shows the target damping torque Tdt containing the main component with a low frequency of about several Hz, and the high frequency component with a higher frequency than it. It is a graph which shows the target damping torque Tdtf after a low-pass filter process. It is a graph which shows the target damping torque Tdta after correction whose driving torque is the target damping torque Tdt before the low-pass filter processing and whose braking torque is the target damping torque Tdtf after the low-pass filtering. It is a graph which shows the target damping torque Tdta after correction in which both the driving torque and the braking torque are the target damping torque Tdtf before the low-pass filter processing. It is a graph which shows the target damping torque Tdta after correction in which the driving torque is the target damping torque Tdtf after the low-pass filter processing and the braking torque is the target damping torque Tdt before the low-pass filtering. It is a flowchart which shows the damping torque control routine in the example of correction. It is a graph corresponding to FIG. 5 which shows the target damping torque Tdta after correction about the correction example.

  Hereinafter, preferred embodiments will be described in detail with reference to the accompanying drawings. In the following description, the vibration on the spring means the vibration generated in the vehicle body when the force applied to the vehicle wheel from the road surface is transmitted to the vehicle body as the spring on the suspension, for example, This refers to vibration including frequency components in the vicinity of 1 to 4 Hz, particularly 1.5 Hz. The vibration on the spring of the vehicle includes pitch vibration and bounce vibration (vertical vibration) of the vehicle. Further, sprung mass damping control refers to control for reducing vibration on a vehicle spring.

  FIG. 1 is a schematic configuration diagram showing one embodiment of a vehicle vibration damping control device 10 according to the present invention applied to a vehicle equipped with a hybrid system. In FIG. 1, a vibration suppression control device 10 includes a hybrid system 14 that is mounted on a vehicle 12 and is a drive source that generates a driving force for running the vehicle 12. The hybrid system 14 includes an engine 16 that is an internal combustion engine and an electric motor 18 that can also function as a generator. Furthermore, the hybrid system 14 includes a generator (motor generator) 20 that receives the output of the engine 16 to generate power, and the engine 16 and the generator 20 are connected to each other by a power split mechanism 22.

  The power split mechanism 22 and the electric motor 18 are connected to each other via a speed reducer 24. The speed reducer 24 includes a differential (not shown) and is connected to left and right front wheels 28FL and 28FR as drive wheels via drive shafts 26L and 26R, respectively. The left and right front wheels 28FL and 28FR are not only driving wheels but also steering wheels, and are steered via a steering mechanism when a steering wheel (not shown) is operated by a driver.

  The power split mechanism 22 distributes the output of the engine 16 to the generator 20 and the speed reducer 24. The speed reducer 24 decelerates the output of the engine 16 and / or the output of the electric motor 18 transmitted via the power split mechanism 22 and transmits them to the left and right front wheels 28FL and 28FR. The speed reducer 24 is provided with a vehicle speed sensor 30 that detects the vehicle speed V by detecting the rotational speed of an output shaft (not shown) of the speed reducer. The power split mechanism 22 also functions as a driving force splitting unit that splits the output of the engine 16 into an output to the generator 20 and a driving force for running the vehicle 12.

  The electric motor 18 is an AC synchronous motor, and is driven by AC power supplied from the inverter 32. The electric motor 18 also functions as a regenerative generator by being driven by the rotation of the left and right front wheels 28FL and 28FR, and applies a regenerative braking force to the front wheels 28FL and 28FR. The electric power generated by the electric power generated by the electric motor 18 is converted from alternating current to direct current by the inverter 32 and charged into a chargeable / dischargeable battery 34. During braking of the vehicle 12, the vehicle 12 is braked by a regenerative braking force generated by the electric motor 18, a friction braking force generated by a friction braking device (not shown), and an engine braking force.

  The inverter 32 converts the electric power stored in the battery 34 from direct current to alternating current and supplies it to the motor 18, and also converts the electric power generated when the generator 20 is driven by the output of the engine 16 from alternating current to direct current. Thus, the battery 34 is stored. Accordingly, the battery 34 functions as a power source for driving the electric motor 18 and also functions as a power storage unit that stores electricity generated by the generator 20. The generator 20 has a configuration as an AC synchronous motor similar to the above-described electric motor 18 and generates power mainly by receiving the output of the engine 16. However, power is supplied from the battery 34 via the inverter 32 as necessary. Can also function as an electric motor.

  The engine 16, the electric motor 18, the generator 20, the power split mechanism 22, and the friction braking device are controlled by the electronic control device 40, thereby controlling the driving force and braking force of the vehicle. Although not shown in detail in FIG. 1, the electronic control unit 40 includes an engine control unit 40A that controls the engine 16 and the power split mechanism 22, and an electric motor control unit 40B that controls the motor 18, the generator 20, and the inverter 32. And a battery control unit 40C that monitors the amount of charge that is the remaining amount of electricity of the battery 34. Furthermore, the electronic control unit 40 includes a braking control unit 40D that controls the braking force of the vehicle.

  As can be understood from the above description, the motor 18, the inverter 32, the motor control unit 40B, and the battery control unit 40C charge the battery 34 with electricity generated by applying braking force to the left and right front wheels 28FL and 28FR by regenerative braking. Functions as a regenerative braking device.

  As shown in FIG. 1, the electronic control device 40 is provided with a signal indicating the vehicle speed V from a vehicle speed sensor 30 provided in the speed reducer 24 and provided in an accelerator pedal 42 operated by a driver. A signal indicating the accelerator opening A is input from the accelerator opening sensor 44. The electronic control unit 40 includes wheel speed sensors 46FL, 46FR, 46RL, and 46RR provided on the left and right front wheels 28FL and 28FR and the left and right rear wheels 28RL and 28RR, respectively. A signal indicating VRR is input.

  Further, the vehicle 12 is provided with an eco switch (ECO-SW) 48 that is operated by a vehicle occupant in order to set the travel mode of the vehicle to an eco mode that reduces its energy consumption. A signal indicating whether or not the switch is on is input from the eco switch 48 to the electronic control unit 40, and further a signal indicating the pressure Pm in the master cylinder not shown in the figure is input. .

  The engine control unit 40A, the motor control unit 40B, the battery control unit 40C, and the braking control unit 40D are controlled by the integrated control unit 40E as necessary, and these control units exchange information and commands with each other as necessary. Do. Each of the above-described control units of the electronic control unit 40 includes a microcomputer having a CPU, a ROM, a RAM, and an input / output port device, which are connected to each other by a bidirectional common bus. Good.

  The integrated control unit 40E calculates the driver's required driving force based on the vehicle speed V, the accelerator opening A, and the like during normal driving of the vehicle, so that the engine driving unit 40A becomes the required driving force. And the output of the engine 16 etc. is controlled via the electric motor control part 40B. In addition, when the vehicle is braked, the integrated control unit 40E calculates the target deceleration of the vehicle based on the pressure Pm in the master cylinder not shown in the drawing so that the deceleration of the vehicle becomes the target deceleration. The friction braking force and the regenerative braking force are controlled via the braking control unit 40D and the motor control unit 40B.

  Control of the driving force and braking force of the vehicle itself is not important to the present invention, and control of the driving force and braking force of a vehicle equipped with a hybrid system is well known in the art. Therefore, further detailed explanation about the control of the driving force and braking force of the vehicle is omitted, but if necessary, refer to, for example, International Publication No. WO2010131341 concerning the applicant's application.

  Furthermore, the integrated control unit 40E performs sprung mass damping control in a situation where the vehicle 12 is traveling and deceleration by braking is not performed. For example, the integrated control unit 40E estimates the motion state and sprung vibration of the vehicle 12 using the vehicle model based on the accelerator opening A and the wheel speeds VFL to VRR, and suppresses the estimated sprung vibration. Therefore, the target damping torque Tdt is calculated as the torque of the hybrid system 14 necessary for this.

  The calculation procedure of the target damping torque Tdt is not important for the present invention and is well known in the art. Therefore, further detailed explanation about the calculation of the target damping torque Tdt is omitted, but if necessary, refer to, for example, Japanese Patent Application Laid-Open No. 2011-17303 related to the applicant of the present application.

  Further, the integrated control unit 40E modifies the target damping torque Tdt according to the flowchart shown in FIG. 2 based on the charge amount Eb of the battery 34 and whether or not the eco switch 48 is on. The later target damping torque Tdta is calculated. The integrated control unit 40E calculates the target travel drive torque Tvet of the engine 16 and the target travel drive torque Tvmt of the electric motor 18 based on the required drive force of the vehicle based on the drive operation of the driver, and the target travel drive torque Tvet is calculated. The signal shown is output to the engine control unit 40A. The engine control unit 40A controls the output of the engine 16 based on the target travel drive torque Tvet. Further, the integrated control unit 40E calculates the target torque Tmt of the electric motor 18 as the sum of the target traveling drive torque Tvmt and the corrected target vibration damping torque Tdta, and the electric motor 18 is set so that the output torque becomes the target torque Tmt. 18 is controlled.

  In particular, the integrated control unit 40E calculates the target vibration damping torque Tdtf after the low-pass filter processing by low-pass filtering the signal indicating the target vibration damping torque Tdt. The integrated control unit 40E calculates a target torque index value Tmi indicating whether or not the target torque of the electric motor 18 is a braking torque as the sum of the target travel drive torque Tvmt and the target vibration damping torque Tdtf. When the charge amount Eb of the battery 34 is equal to or greater than the reference value Ebc (positive constant) for preventing overcharge and the index value Tmi of the target torque is the braking torque, the integrated control unit 40E performs overcharge of the battery 34. Limit regenerative braking to prevent it. That is, the integrated control unit 40E sets the corrected target damping torque Tdta to the target damping torque Tdtf after the low-pass filter process. Furthermore, when the magnitude of the target torque Tmt exceeds the limit reference value Td0, the integrated control unit 40E corrects the target torque Tmt to the limit reference value Td0.

  The limit reference value Td0 may be a negative constant set in advance. However, the limit reference value Td0 may be variably set according to the charge amount Eb so that the size decreases as the charge amount Eb of the battery 34 increases. The magnitude of the limit reference value Td0 is a protective circuit (see FIG. 4) that is provided in the regenerative braking device and protects the battery 34 and the like from overvoltage, regardless of whether the reference value is a negative constant or variably set. It is below the protection standard value in (not shown).

  As can be understood from the above description, the vibration suppression control device 10 includes the hybrid system 14, the inverter 32, the battery 34, the electronic control device 40, the wheel speed sensors 46FL to 46RR, and the like. The vibration suppression control device 10 calculates and corrects the target vibration suppression torque Tdt and controls the vibration suppression torque by controlling the electric motor 18 of the hybrid system 14 described above.

  Next, a control routine for correcting the target damping torque Tdt in the embodiment will be described with reference to the flowchart shown in FIG. The control according to the flowchart shown in FIG. 2 is repeated every predetermined time when the vehicle speed V detected by the vehicle speed sensor 30 is equal to or higher than the reference value V0 (positive constant) and deceleration by braking is not performed. Executed. In the following description, the correction control of the target damping torque Tdt according to the flowchart shown in FIG. 2 is simply referred to as “control”.

  The target damping torque Tdt, the target damping torque Tdtf after the low-pass filter process, and the corrected target damping torque Tdta are positive and negative values, respectively, when they are the driving torque and the braking torque. And Furthermore, “+” and “−” for the target vibration damping torque Tdt and the target vibration damping torque Tdtf after the low-pass filter processing mean that they are drive torque and braking torque, respectively.

  First, in step 10, a signal indicating the target travel drive torque Tvmt, a signal indicating the target damping torque Tdt, a signal indicating the wheel speeds VFL to VRR detected by the wheel speed sensors 46FL to 46RR, and the like are read.

  In step 20, the target vibration damping torque Tdt is subjected to low pass filter processing, whereby the target vibration damping torque Tdtf after low pass filter processing is calculated. Therefore, this step 20 functions as a filter device that performs low-pass filter processing on the signal indicating the target damping torque.

  In step 30, a target torque index value Tmi of the electric motor 18 is calculated as the sum of the target travel drive torque Tvmt and the target vibration damping torque Tdtf. Therefore, this step 30 functions as an index value calculation device that calculates the index value Tmi of the target torque.

  In step 40, it is determined whether or not the charge amount Eb of the battery 34 detected by the battery control unit 40C is greater than or equal to the reference value Ebc, that is, the charging of the battery 34 by the electric power generated by regenerative braking is limited. A determination is made as to whether it should be. When a negative determination is made, control proceeds to step 110, and when an affirmative determination is made, control proceeds to step 50.

  In step 50, it is determined whether or not the eco switch 48 is on, that is, whether or not the power supply by discharging the battery 34 should be restricted in order to reduce the energy consumption of the vehicle 12. Done. When an affirmative determination is made, the control proceeds to step 80, and when a negative determination is made, the control proceeds to step 60.

  In steps 60, 80, 120, and 140, it is determined whether or not the target torque index value Tmi is negative, that is, the target torque of the electric motor 18 is substantially the braking torque, and the regenerative braking force should be generated. It is determined whether or not. If an affirmative determination is made in step 60, the control proceeds to step 100. If a negative determination is made, in step 70, the corrected target damping torque Tdta is the target damping torque Tdt (+) before the low-pass filter processing. Set to

  If a negative determination is made in step 80, the corrected target damping torque Tdta is set in step 90 to the target damping torque Tdtf (+) after the low-pass filter process. On the other hand, when an affirmative determination is made in step 80, the corrected target damping torque Tdta in step 100 is set to the target damping torque Tdtf (−) after the low-pass filter process.

  Also in step 110, as in step 50, it is determined whether or not the eco switch 48 is on. When an affirmative determination is made, the control proceeds to step 140, and when a negative determination is made, the control proceeds to step 120.

  If an affirmative determination is made in step 120, the control proceeds to step 160. If a negative determination is made, the corrected target damping torque Tdta in step 130 is the target damping torque Tdt (+) before the low-pass filter processing. Set to

  If a negative determination is made in step 140, the corrected target damping torque Tdta is set in step 150 to the target damping torque Tdtf (+) after the low-pass filter process. On the other hand, when an affirmative determination is made in step 140, the corrected target damping torque Tdta in step 160 is set to the target damping torque Tdt (−) before the low-pass filter processing.

  When steps 70, 90, 100, 130, 150 and 160 are completed, the control according to the flowchart shown in FIG.

  As can be seen from the above description, the target damping torque Tdt is determined based on whether or not the charge amount Eb of the battery 34 is greater than or equal to the reference value Ebc (step 40) and whether or not the eco switch 48 is on (step 50, 110), the target damping torque Tdtf after the low-pass filter processing is corrected according to whether it is negative (steps 60, 80, 120 and 140). In particular, steps 50 and 110 function as a restriction determination device that determines whether or not the supply of power due to the discharge of the battery 34 should be restricted.

  Next, the operation of the above-described embodiment will be described with respect to the charge amount Eb of the battery 34 and the like according to the situation. In the following description, the target travel drive torque Tvmt is 0 so that the embodiment can be easily understood. Therefore, the target torque index value Tmi is the same as the target damping torque Tdtf after the low-pass filter processing. Assume that there is. Furthermore, it is assumed that the target damping torque Tdt includes a main component having a low frequency of about several Hz and a high frequency component having a higher frequency than that, as shown in FIG. FIG. 4 shows the target damping torque Tdtf obtained by subjecting the target damping torque Tdt shown in FIG. 3 to low pass filter processing.

  In FIG. 4 and FIGS. 5 to 7 described later, Td0 represents the above-described limit reference value for preventing the battery 34 from being overcharged. The corrected target damping torque Tdta is set to the limit reference value Td0 when the magnitude of the target damping torque Tdt exceeds the limit reference value Td0. Similarly, in FIGS. 3, 4 and 5, Td0 ′ represents a limit reference value for preventing overcharge of the battery in the conventional vibration damping control device. In the conventional vibration damping control device, when the magnitude of the target damping torque Tdt exceeds the limit reference value Td0 ′, the magnitude of the braking torque due to regenerative braking is larger than the limit reference value Td0 ′. Is blocked. As will be described later, the size of the limit reference value Td0 is larger than the size of the limit reference value Td0 ′.

<A-1. When the charge amount Eb is equal to or greater than the reference value Ebc and the eco switch 48 is off>
In this case, an affirmative determination is made in step 40, but a negative determination is made in step 50. Therefore, when the target torque index value Tmi is positive or 0, the corrected target damping torque Tdta is set to the target damping torque Tdt (+) before the low-pass filter processing in steps 60 and 70. On the other hand, when the target torque index value Tmi is negative, the corrected target damping torque Tdta is set to the target damping Tdtf (−) after the low-pass filter processing in steps 60 and 100.

  Therefore, as shown in FIG. 5, the corrected target damping torque Tdta is a positive value of the target damping torque Tdt shown in FIG. 3 in the case of drive torque. Further, in the case of braking torque, the corrected target damping torque Tdta is a negative value of the target damping torque Tdtf after the low-pass filter processing shown in FIG. Although not shown in FIG. 5, the corrected target damping torque Tdta is set to Td0 in the range where the magnitude of the target damping torque Tdtf is larger than the limit reference value Td0.

<A-2. When the charge amount Eb is greater than or equal to the reference value Ebc and the eco switch 48 is on>
In this case, an affirmative determination is made in steps 40 and 50. Therefore, when the target torque index value Tmi is positive or 0, the corrected target damping torque Tdta is set to the target damping torque Tdtf (+) after the low-pass filter processing in steps 80 and 90. On the other hand, when the index value Tmi of the target torque is negative, the corrected target damping torque Tdta is set to the target damping Tdtf (−) after the low pass filter processing in steps 80 and 100.

  Therefore, the corrected target damping torque Tdta is the value of the target damping torque Tdtf after the low-pass filter processing shown in FIG. 4, that is, the high frequency component, in both cases of the driving torque and the braking torque. The value is not included. Although not shown in FIG. 4, the target damping torque Tdtf after the low-pass filter processing is the braking torque, and the corrected target damping torque is within a range in which the magnitude is larger than the limit reference value Td0. Tdta is set to Td0.

<B-1. When the charge amount Eb is less than the reference value Ebc and the eco switch 48 is off>
In this case, a negative determination is made in steps 40 and 110. Accordingly, when the target torque index value Tmi is positive or 0, the corrected target damping torque Tdta is set to the target damping torque Tdt (+) before the low-pass filter processing in steps 120 and 130. On the other hand, when the target torque index value Tmi is negative, the corrected target damping torque Tdta is set to the target damping Tdt (−) before the low-pass filter processing in steps 120 and 160.

  Accordingly, the corrected target damping torque Tdta is the target damping before the low-pass filter processing shown in FIG. 3 in both cases of the driving torque and the braking torque as shown in FIG. It becomes the same value as the torque Tdt, that is, a value including a high frequency component. Although not shown in FIG. 6, when the target damping torque Tdt is the braking torque and the magnitude thereof is larger than the limit reference value Td0, the corrected target damping torque Tdta is set to Td0. Is done.

<B-2. When the charge amount Eb is less than the reference value Ebc and the eco switch 48 is on>
In this case, a negative determination is made in step 40, but an affirmative determination is made in step 110. Therefore, when the target torque index value Tmi is positive or 0, the corrected target damping torque Tdta is set to the target damping torque Tdtf (+) after the low-pass filter processing in steps 140 and 150. On the other hand, when the target torque index value Tmi is negative, the corrected target damping torque Tdta is set to the target damping Tdt (−) before the low-pass filter processing in steps 140 and 160.

  Therefore, the corrected target damping torque Tdta is a positive value of the target damping torque Tdtf after the low-pass filter processing shown in FIG. That is, the value does not include a high-frequency component, and in the case of the braking torque, the value is a negative value of the target damping torque Tdt shown in FIG. In this case, the corrected target damping torque Tdta is not limited by the limit reference value Td0.

  Of the above four cases, the charge amount Eb is equal to or greater than the reference value Ebc, and charging of the battery 34 by regenerative braking needs to be limited in the cases of A-1 and A-2. In these cases, the corrected negative value (braking torque) of the target damping torque Tdta is a value that does not include a high-frequency component, and is corrected to a value that does not exceed the limit reference value Td0. It is set (FIGS. 4 and 5). Therefore, it is possible to effectively prevent the battery 34 from being overcharged by regenerative braking due to the magnitude of the damping torque exceeding the limit reference value Td0 when the braking torque is applied.

As described above, the amount of charge by regenerative braking for the battery 34 not only increases as the damping torque Tdt increases, but also increases as the damping torque frequency increases. For example, if the damping torque is Td and the rotational angular velocity of the motor 18 is ω, the charging rate P (charge amount per unit time) for the battery 34 due to the motor 18 functioning as a regenerative generator is expressed by the following formula ( 1).
P = Td · ω (1)

When the inertia moment of rotation of the electric motor 18 is I and the rotational angular acceleration of the electric motor 18 is ωd, the vibration damping torque Td due to the rotation of the electric motor 18 is expressed by the following equation (2).
Td = I · ωd (2)

Assuming that the frequency of the damping torque Td is f, the rotational angular velocity when the electric motor 18 is rotated to generate the damping torque Td is expressed by the following equation (3). Is represented by the following formula (4).
ω = 2π · f (3)
ωd = 2π · 2π · f = (2π) ² · f (4)

By substituting the above formulas (2) to (4) into the above formula (1), the charging rate P is expressed by the following formula (5). From the following equation (5), since the charging rate P is a function of the square of the frequency f of the damping torque, the charging rate P increases as the damping torque frequency f increases, and the rate of increase is larger than in the proportional case. I understand that.
P = I · (2π) ² · f · 2π · f = I · (2π) ³ · f ² (5)

  According to the above-described embodiment, in the case of A-1 and A-2, the corrected target damping torque Tdta for the braking torque does not include a high frequency component. Therefore, the frequency f of the damping torque Tdt can be lowered as compared with the case of the conventional damping control device in which the target damping torque Tdt is not subjected to the low-pass filter processing. Can be reduced. Therefore, the limit reference value Td0 for preventing overcharge of the battery 34 can be made larger than the limit reference value Td0 ′ in the case of the conventional vibration damping control device. As a result, the restriction on the magnitude of the damping torque can be relaxed, so that the damping effect of the low-frequency sprung vibration with a high necessity for damping is improved as compared with the case of the conventional damping control device. be able to.

  Further, according to the above-described embodiment, the target damping torque Tdta at the time of the braking torque is corrected so as not to exceed the limit reference value Td0. Therefore, even when the target damping torque Tdt before correction exceeds the limit reference value Td0, the voltage of the regenerative current applied to the protection circuit of the regenerative braking device is limited to a voltage corresponding to the limit reference value Td0. be able to. Therefore, even when the target damping torque includes a high frequency component and the magnitude of the target damping torque before correction becomes a large value due to the high frequency component, an excessive regenerative current is generated in the protection circuit of the regenerative braking device. The application of voltage can be avoided, and the durability of the protection circuit can be improved.

  According to the above-described embodiment, even when the charge amount Eb of the battery is equal to or greater than the reference value Ebc, when the target vibration damping torque Tdtf after the low-pass filter process is a positive value and the driving torque, the target vibration damping is performed. The torque Tdt is not corrected to the low-pass filtered value Tdtf. Therefore, when the necessary damping torque is the driving torque, the damping torque can be controlled based on the target damping torque Tdt from which the high frequency component is not removed. Therefore, the vibration on the spring can be effectively damped as compared with the case where the target damping torque is corrected to the value subjected to the low-pass filter processing regardless of whether or not the damping torque is the braking torque.

  Further, according to the above-described embodiment, in the case of the above-described A-2 and B-2, that is, when the eco switch 48 is on, the corrected target damping torque Tdta for the driving torque is The target damping torque Tdtf (+) after the low-pass filter processing is set. Therefore, even when the eco switch 48 is on, the power consumed by controlling the damping torque is reduced as compared with the case where the damping torque is controlled based on the target damping torque Tdt including a high frequency component. Can be used.

For example, the root mean square (RMS) of the drive torque of the target damping torque Tdt shown in FIG. 3 is 18.1 Nm. On the other hand, the root mean square of the driving torque of the corrected target damping torque Tdta shown in FIGS. 4 and 7 is 23.4 Nm. Therefore, according to the above-described embodiment, in the case of the illustrated example, when controlling the damping torque, it is possible to achieve the energy saving rate of 23% obtained by the following equation (6).
(23.4-18.1) /23.4×100=23% (6)

  Furthermore, according to the above-described embodiment, whether or not the required damping torque is the braking torque is determined by determining whether the target torque index value Tmi is negative in steps 60, 80, 120 and 140. This is done by determining whether or not. Therefore, compared with the case where the determination whether the necessary damping torque is the braking torque is performed by the determination whether the target torque Tmt including the high frequency component is negative, it is caused by the high frequency component. It is possible to prevent the determination result from frequently changing.

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are possible within the scope of the present invention. This will be apparent to those skilled in the art.

  For example, in the above-described embodiment, whether or not the necessary damping torque is the braking torque is determined by determining whether or not the target torque index value Tmi is negative in steps 60, 80, 120, and 140. This is done by discrimination. In other words, the processing reference value is zero. However, as shown in FIG. 8 as a modification example, a negative value smaller than 0 and larger than the limit reference value Td0 is set as a processing reference value Tdp, and the determination reference values in steps 60, 80, 120, and 140 are The processing reference value Tdp may be changed.

  The processing reference value Tdp may be a negative constant, but is variably set according to the charge amount Eb so that the larger the charge amount Eb of the battery 34 is, the smaller the size is like the limit reference value Td0. May be.

  According to this modified example, when the target torque index value Tmi is negative and the magnitude is 0 or more and the processing reference value Tdp or less, the modified target damping torque Tdta is shown in FIG. 9 corresponding to FIG. As shown, it is set to the target vibration damping torque Tdt before the low-pass filter processing including the high frequency component. Therefore, when the index value Tmi of the target torque is negative and the magnitude is not less than 0 and not more than the processing reference value Tdp, the high-frequency component can also be damped. When the target torque index value Tmi is negative and the magnitude is not less than 0 and not more than the processing reference value Tdp, the magnitude of the corrected target damping torque Tdta does not become excessively large. The charging rate of the battery 34 does not increase excessively due to the inclusion of the high frequency component.

  In the above-described embodiment, when the battery charge amount Eb is equal to or greater than the reference value Ebc and the target torque index value Tmi is the braking torque, the target torque Tmt does not exceed the limit reference value Td0. , Modified as necessary. However, the restriction on the magnitude of the target torque Tmt performed at the restriction reference value Td0 when the target torque Tmt is the braking torque may be omitted.

  In the above-described embodiment, the determination as to whether the required damping torque is the braking torque is performed by determining whether the target torque index value Tmi is negative. The index value Tmi is the sum of the target travel drive torque Tvmt and the target vibration damping torque Tdtf. However, the target torque index value Tmi may be the sum (Tmt) of the target travel drive torque Tvmt and the target damping torque Tdt before the low-pass filter processing, and the target travel drive torque Tvmt and the target before the low-pass filter processing. It may be a value after the low-pass filter processing of the sum with the damping torque Tdt.

  In the above-described embodiment, the vehicle 12 is provided with the eco switch 48 operated by the vehicle occupant in order to set the travel mode of the vehicle to the eco mode that reduces energy consumption. However, the vibration suppression control device 10 of the present invention may be applied to a vehicle in which the eco switch 48 is not provided. In that case, steps 50, 80 and 90 in the flowcharts shown in FIGS. 2 and 8 are omitted, and steps 110, 140 and 150 are omitted.

  In the above-described embodiment, the vehicle 12 is a hybrid system-equipped vehicle having the hybrid system 14 as a drive source. However, as long as the braking torque is generated as the braking torque by the regenerative braking and the electric power generated by the regenerative braking is charged to the battery, the vibration suppression control device 10 of the present invention can be applied to an electric vehicle or a fuel cell vehicle. Good.

  Furthermore, in the above-described embodiment, the hybrid system 14 is a two-motor parallel type hybrid system. However, the hybrid system when the vibration damping control device 10 of the present invention is applied to a vehicle equipped with a hybrid system may be a one-motor parallel type hybrid system, or another type of hybrid system such as a series type. It may be.

DESCRIPTION OF SYMBOLS 10 ... Vibration suppression control device, 12 ... Vehicle, 14 ... Hybrid system, 16 ... Engine, 18 ... Electric motor, 20 ... Generator, 32 ... Inverter, 34 ... Battery, 40 ... Electronic control device

Claims (3)

A chargeable / dischargeable battery, an electric motor that generates driving torque using electricity from the battery, and a regenerative braking torque generated by causing the electric motor to function as a regenerative generator. A regenerative braking device that applies braking force to the wheels and charges the battery with the generated electricity, calculates a target damping torque for damping vibration on a spring during traveling of the vehicle, and This is the sum of the target travel drive torque of the motor and the target vibration suppression torque for driving the vehicle so that the actual vibration suppression torque generated by the drive torque and the regenerative braking torque becomes the target vibration suppression torque. In a vehicle vibration suppression control device including a control means for controlling the electric motor and the regenerative braking device based on a target torque,
The vibration suppression control device includes a charge amount detection device that detects a charge amount of the battery, an index value calculation device that calculates an index value of a target torque indicating whether the target torque is a braking torque, and the target A filter device for low-pass filtering the signal indicating the damping torque,
The control means corrects the target damping torque to a value indicated by the signal after the low-pass filter processing when the charge amount of the battery is equal to or greater than a reference value and the index value of the target torque is a braking torque. Configured as
Vehicle vibration control device.   2. The vehicle vibration damping control device according to claim 1, wherein the control means is a braking torque in which a charge amount of the battery is equal to or larger than a reference value and an index value of the target torque is larger than a processing reference value. A vehicle vibration damping control device configured to correct the target vibration damping torque to a value indicated by a signal after low-pass filter processing at a certain time. The vehicle vibration damping control device according to claim 1 or 2,
The vibration suppression control device includes a limit determination device that determines whether or not the supply of power due to discharging of the battery is to be limited.
In a situation where the supply of electric power due to discharging of the battery is to be restricted, the control means determines the target vibration damping torque as a signal after the low-pass filter processing when the index value of the target torque is a drive torque. A vibration suppression control device for a vehicle configured to be corrected to a value indicated by.

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