Pedal-operated control device
The pedal-type operating device addresses discomfort in electric vehicles by vibrating the pedal at specific frequencies to improve tactile feedback, enhancing braking precision and smoothness.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- SUBARU CORP
- Filing Date
- 2022-03-30
- Publication Date
- 2026-07-09
Smart Images
Figure 0007887272000001 
Figure 0007887272000002 
Figure 0007887272000003
Abstract
Description
Technical Field
[0001] The present invention relates to a pedal-type operating device used for driving operations of a vehicle and the like.
Background Art
[0002] For example, in a vehicle such as an automobile, it is known to perform an acceleration operation (accelerator operation) and a deceleration operation (brake operation) by a foot-operated pedal-type operating device (accelerator pedal, brake pedal). In recent years, in an electric vehicle, there is known a so-called one-pedal type in which an acceleration operation and a braking operation by a regenerative brake are respectively performed by a stepping operation and a returning operation of a single pedal.
[0003] As a technology related to a pedal-type operating device for a vehicle, for example, in Patent Document 1, in order to surely notify a driver of information, a reaction force adding means for adding a reaction force according to a stepping operation of a pedal member and a vibration means for vibrating the pedal member are provided, and based on the resonance frequency of the pedal member, it is described that the vibration frequency of the vibration by the vibration means is controlled. In Patent Document 2, in order to surely present information without giving discomfort or a sense of incongruity to a driver, at least one of the vibration frequency, the vibration presentation time, the vibration amplitude, and the presentation time interval of a plurality of vibrators is adjusted to match the human tactile sensation characteristics, and a warning for indicating a detected dangerous state is presented by applying vibration to a selected plurality of vibrators that vibrate a pedal or the like in a predetermined order so that a virtual motion phenomenon is perceived by the driver. A vehicle information presentation device is described.
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Patent Document 2
Summary of the Invention
[0005] In electric vehicles such as BEVs (battery electric vehicles) and HEVs (engine hybrid electric vehicles), acceleration and braking using regenerative braking can be performed using a single pedal (typically the accelerator pedal). Thus, by enabling both acceleration and braking with a single pedal, it is possible to reduce fatigue caused by switching between pedals when accelerating and braking, and to shorten the coasting time before braking that results from switching pedals. Furthermore, it is possible to improve the energy efficiency of the vehicle by increasing the frequency of regenerative braking.
[0006] However, if braking is performed by releasing the accelerator pedal, for example, it may be difficult to fine-tune the braking force, which could give the driver a sense of discomfort. In other words, when braking using a normal brake pedal, the driver feels the pressure on their foot (pressure gradient and correlation of pressure with the amount of movement) to operate and adjust the brakes. However, when braking by releasing the accelerator pedal, the movement is in the direction of releasing force, so the contact surface between the foot and the pedal tends to decrease, making it more difficult to feel the pressure (pressure change). In particular, in the case of brake-by-wire systems, where the brake pedal does not have a mechanical connection to the braking system, vibrations transmitted to the pedal during braking are less noticeable, similar to those in hydraulic friction brakes. Therefore, drivers will have to adjust the amount of pedal input after recognizing the vehicle's deceleration based on the deceleration acceleration and the vehicle's pitching behavior. However, in this case, there is a concern that the driver's preparation for braking will be insufficient, resulting in a sudden or unnatural feeling. In view of the above-mentioned problems, the object of the present invention is to provide a pedal-type operating device that can improve the accuracy of the return operation performed by the occupant. [Means for solving the problem]
[0007] To solve the above-mentioned problems, the pedal-type operating device of the present invention is a pedal-type operating device in which the operation of a vehicle is performed by a foot pedal, comprising: an excitation unit that excites the pedal; an motion detection unit that detects the movement of the pedal; and, in accordance with the return movement of the pedal detected by the motion detection unit, the excitation unit emits a frequency of 10 to 50 Hz bandwidth and frequencies between 100 and 300 Hz bandwidth At least On the other hand The system comprises an excitation control unit that excites the pedal with an excitation waveform, the pedal having a function to perform a braking operation that increases the braking force according to the amount of operation in the return direction, and a function to perform a driving force operation that increases the driving force according to the amount of operation in the pressing direction in a region of the movable range in which the braking force is not generated, and the excitation control unit is characterized in that it increases the amplitude of the excitation waveform in accordance with the increase in braking force corresponding to the braking operation. Human perception of operating force (reaction force) involves both proprioception and cutaneous sensation, and the reaction force is perceived through the response of corresponding receptors. In the initial stages of pedaling, where the reaction force is minute, cutaneous sensation becomes dominant. According to this, by vibrating the pedal in response to the pedal's return motion, at least one of the frequency ranges in which Pacinian corpuscles (receptors that control cutaneous sensation) are well-sensitive (100 to 300 Hz) and Meissner corpuscles (receptors that control cutaneous sensation) is well-sensitive (10 to 50 Hz), these receptors are stimulated, making it easier for the driver to feel the pressure on the soles of their feet. In particular, this effect can be obtained more effectively by vibrating the pedal in the frequency range in which Pacinian corpuscles, which are considered to have the fastest response in cutaneous sensation, are well-sensitive. This improves the spatial resolution with which the driver perceives the amount of pedal movement, even in return movements where the driver usually doesn't feel much resistance from the pedal, enabling more precise pedal operation. Therefore, it is possible to improve the ease of driving and the smoothness of the vehicle's ride. In this case, the system can be configured to adjust the amplitude of the excitation waveform so that it is amplified in accordance with the increase in the amount of regenerative braking. According to this, by varying the strength of the braking force, the predictability of when regenerative braking will begin can be improved, further enhancing operability.
[0008] In the present invention, the motion detection unit can be configured to detect the operating speed of the pedal, and the vibration control unit can be configured to increase the amplitude of the vibration waveform in accordance with the increase in the operating speed. According to this, by increasing the amplitude of the excitation waveform in accordance with the increasing pedal operating speed, it is possible to effectively improve the driver's perception of the reaction force when releasing the pedal. In particular, when the operating speed is fast, increasing the excitation amplitude emphasizes the feeling of reaction force (pressure), allowing the driver to perceive a change in accordance with the operating speed, and this can act as a damping term.
[0009] In the present invention, the pedal has a function of performing a braking operation that increases the braking force according to the amount of operation in the return direction, and the vibration control unit can be configured to increase the amplitude of the vibration waveform in accordance with the increase in braking force corresponding to the braking operation. According to this, even when braking is performed with a return operation that is difficult to perceive in relation to the downward movement of the pedal, it is possible to improve the spatial resolution of the occupant's pedal movement and enable precise braking.
[0010] In the present invention, the pedal can be configured to have a function of performing a driving force operation that increases the driving force according to the amount of operation in the direction of pressing in the region of the movable range in which no braking force is generated. According to this, in a so-called one-pedal type pedal control system in which both acceleration and braking are performed with a single pedal, it is possible to suppress the problem of braking becoming more difficult than acceleration, which would impair the smoothness of driving.
[0011] In the present invention, a vibration input detection unit is provided for detecting vibration input from the road surface, and the excitation control unit can be configured to increase the amplitude of the excitation waveform in accordance with the increase in the amplitude of the vibration input. According to this, even if vibrations transmitted from the road surface increase due to factors such as a rough road surface or tire pattern, the above-mentioned effects can be ensured by increasing the amplitude of the excitation waveform. Here, as the vibration input detection unit, for example, an acceleration sensor that detects the acceleration of the unsprung portion of the vehicle (the part that moves relative to the vehicle body in accordance with the stroke of the suspension system), or a torque sensor that detects the torque acting on the steering shaft in a power steering system can be used. Here, the vibration control unit can be configured to extract a specific frequency band of vibration input from the road surface (typically a band including 100 to 300 Hz) and increase the amplitude of the excitation waveform in accordance with the increase in amplitude in the extracted band. To solve the above-mentioned problems, the pedal-type operating device of the present invention is a pedal-type operating device in which the operation of a vehicle is performed by a foot pedal, comprising: an excitation unit that excites the pedal; an motion detection unit that detects the movement of the pedal; and, in accordance with the return movement of the pedal detected by the motion detection unit, the excitation unit emits a frequency of 10 to 50 Hz bandwidth and frequencies between 100 and 300 Hz bandwidth At least On the other hand The device comprises a vibration control unit that vibrates the pedal with an excitation waveform, and a vibration input detection unit that detects vibration input from the road surface, wherein the motion detection unit detects the operating speed of the pedal, and the vibration control unit increases the amplitude of the excitation waveform in accordance with the increase in the operating speed, and increases the amplitude of the excitation waveform in accordance with the increase in the amplitude of the vibration input. To solve the above-mentioned problems, the pedal-type operating device of the present invention is a pedal-type operating device in which the operation of a vehicle is performed by a foot pedal, comprising: an excitation unit that excites the pedal; an motion detection unit that detects the movement of the pedal; and, in accordance with the return movement of the pedal detected by the motion detection unit, the excitation unit emits a frequency of 10 to 50 Hz bandwidth and frequencies between 100 and 300 Hz bandwidth At least On the other handA vibration control unit that vibrates the pedal with a vibration waveform, and a vibration input detection unit that detects vibration input from the road surface. The pedal has a function of performing a braking operation that increases the braking force according to the operation amount in the return direction. The vibration control unit increases the amplitude of the vibration waveform according to an increase in the braking force corresponding to the braking operation, and increases the amplitude of the vibration waveform according to an increase in the amplitude of the vibration input. In order to solve the above problems, the pedal-type operation device of the present invention is a pedal-type operation device in which a driving operation of a vehicle is performed by a foot-operated pedal, and includes a vibration unit that vibrates the pedal, an operation detection unit that detects the operation of the pedal, and according to the return operation of the pedal detected by the operation detection unit, the vibration unit is vibrated at a frequency of 10 to 50 Hz bandwidth and a frequency of 100 to 300 Hz bandwidth and at least On the other hand It includes a vibration control unit that vibrates the pedal with a vibration waveform. The pedal has a function of performing a braking operation that increases the braking force according to the operation amount in the return direction. The vibration control unit continuously vibrates the pedal to the vibration unit while the braking force is generated by the return operation of the pedal.
Effect of the Invention
[0012] As described above, according to the present invention, it is possible to provide a pedal-type operation device that can improve the accuracy of the return operation by the occupant.
Brief Description of the Drawings
[0013] [Figure 1] It is a diagram schematically showing the configuration of an embodiment of a pedal-type operation device to which the present invention is applied. [Figure 2] It is a schematic diagram showing the configuration of a pedal unit in an embodiment. [Figure 3] It is a diagram schematically showing the configuration of a vibrator control unit in an embodiment. [Figure 4] It is a diagram schematically showing an example of a vibration waveform in an embodiment. [Figure 5]This diagram schematically shows the timing of electrical pulses emitted by receptors when the skin is subjected to pressure. [Figure 6] This figure shows the sensitivity distribution of Pacinian corpuscles and Meissner corpuscles to different frequencies. [Figure 7] This diagram schematically shows an example of gain adjustment in the first gain adjustment section. [Figure 8] This diagram schematically shows an example of gain adjustment in the second gain adjustment section. [Figure 9] This diagram schematically shows an example of the output history of an accelerometer. [Figure 10] This diagram schematically illustrates the method for calculating torque amplitude in the vibration amplitude calculation unit. [Figure 11] This diagram schematically shows an example of gain adjustment in the third gain adjustment section. [Modes for carrying out the invention]
[0014] The following describes an embodiment of a pedal-operated device to which the present invention is applied. The pedal-type control device of this embodiment is installed, for example, in an automobile (vehicle) such as a passenger car, and allows the driver to perform acceleration (accelerator operation) and gentle braking using regenerative braking by operating the pedal with their foot. Examples of vehicles include electric vehicles such as battery electric vehicles (BEVs), engine-electric hybrid vehicles (HEVs), and fuel cell vehicles (FCVs), which use a motor generator with a permanent magnet synchronous motor as their power source. Figure 1 is a schematic diagram showing the system configuration of a vehicle having a pedal-type operating device (accelerator pedal) according to an embodiment. Figure 2 is a schematic diagram showing the configuration of the pedal section in the embodiment.
[0015] Vehicle 1 includes a brake control unit 100, a hydraulic control unit 200, a motor-generator control unit 300, an accelerator pedal 30 (see Figure 2), a power steering control unit 400, a vibrator control unit 500, and the like. Each of these units comprises a microcontroller having an information processing unit such as a CPU, a storage unit such as RAM or ROM, an input / output interface, and a bus to connect them. Furthermore, each unit can communicate with one another, either via an in-vehicle LAN such as a CAN communication system, or directly.
[0016] The brake control unit 100 coordinately controls the hydraulic friction brake and the regenerative braking system in response to the operation of a brake pedal (not shown). Furthermore, the brake control unit 100 has functions for anti-lock brake control and behavior stabilization control. Anti-lock brake control periodically reduces the braking force on a wheel when it detects wheel lock, which occurs when the wheel's rotation becomes stuck during braking. Vehicle stabilization control generates a yaw moment in the restoring direction by using the difference in braking force between the left and right wheels when understeer or oversteer behavior occurs. The brake control unit 100 is connected to a vehicle speed sensor 101, an acceleration sensor 102, a brake pedal sensor 110, and a reaction force generating device 120. Furthermore, the brake system of vehicle 1 also includes a master cylinder 130.
[0017] The vehicle speed sensor 101 is installed in a hub bearing housing (not shown) that rotatably supports the wheels and generates a vehicle speed signal corresponding to the rotational angular velocity of each wheel. The brake control unit 100 calculates the vehicle speed (vehicle speed) of vehicle 1 based on the output of the vehicle speed sensor 101.
[0018] The acceleration sensor 102 is located in the so-called unsprung portion of a suspension device (not shown) that supports the wheel so as to be able to stroke relative to the vehicle body. The acceleration sensor 102 detects the vertical acceleration of a component located on the lower side of a spring, such as a suspension arm or a hub bearing housing. The acceleration sensor 102 is a vibration input detection unit that detects vibration input from the road surface. Furthermore, the brake control unit 100 is equipped with a vehicle body longitudinal acceleration sensor, a vehicle body lateral acceleration sensor, a yaw rate sensor, and the like (not shown) for the purpose of the aforementioned behavior stabilization control.
[0019] The brake pedal sensor 110 has an encoder that detects the amount of brake pedal operation (depression amount). The reaction force generating device 120 generates a reaction force in the direction that returns the brake pedal to its initial position (the position where it is not pressed) in response to a command from the brake control unit 100. The reaction force generating device 120 generates a reaction force using a drive power source such as an electric actuator, for example, when regenerative braking is used.
[0020] The master cylinder 130 pressurizes the brake fluid, which is the working fluid for the friction brake, in response to the pressing motion of the brake pedal tread. The brake fluid pressure generated by the master cylinder 130 is transmitted to the hydraulic control unit 200 via piping.
[0021] The hydraulic control unit (HCU) 200 is a hydraulic pressure control device that has the function of individually adjusting the brake fluid hydraulic pressure of the wheel cylinder 210 of each wheel. The hydraulic control unit 200 includes an electric pump for pressurizing the brake fluid, as well as pressure boosting valves, pressure reducing valves, and pressure holding valves for controlling the brake fluid pressure in each wheel cylinder.
[0022] The hydraulic control unit 200 is connected to the master cylinder 130, wheel cylinder 210, and other components via brake fluid piping. The brake fluid pressure generated by the master cylinder 130 is transmitted to the wheel cylinder 210 via the hydraulic control unit 200. The hydraulic control unit 200 has the function of overriding the brake fluid pressure generated by the master cylinder 130 to increase or decrease the brake fluid pressure of each wheel cylinder. The wheel cylinder 210 is provided on each wheel and, for example, presses the brake pad against the disc rotor, generating a frictional force (braking force) corresponding to the brake fluid pressure.
[0023] Furthermore, in the regenerative cooperative control of the brake control unit 100, if the control share ratio of regenerative braking occurs or increases, the hydraulic control unit 200 is equipped with a function to reduce or shut off the hydraulic pressure of the brake fluid transmitted from the master cylinder 130. In this case, in order to give the driver a feeling that simulates the use of a hydraulic friction brake, the brake control unit 100 uses the reaction force generating device 120 to generate a reaction force on the brake pedal. Furthermore, the brake control unit 100 has a function to perform gentle braking using regenerative braking (for example, a deceleration of up to approximately 0.1 to 0.3G) in response to the return movement of the accelerator pedal 30 from a predetermined position. The brake control unit 100 has a function that allows the occupant to select from multiple levels of maximum braking force from regenerative braking in response to the operation of the accelerator pedal 30.
[0024] The motor-generator control unit 300 comprehensively controls the motor-generator 310 and its auxiliary equipment. The motor generator 310 is a rotating electric machine used as a power source for the vehicle 1. The motor-generator control unit 300 includes an inverter or the like for supplying power from a power source such as a traction battery to the motor-generator 310.
[0025] The motor generator 310 can be, for example, mounted on the vehicle body (sprung mass) and transmit driving force to the wheels via a differential, drive shaft, etc., but is not limited to this configuration; for example, it may be an in-wheel motor. The motor-generator control unit 300 switches between a drive mode in which the motor-generator 310 generates output torque and a regenerative power generation mode in which the motor-generator 310 performs regenerative power generation, absorbs torque transmitted from the wheels, and generates braking force.
[0026] In drive mode, the motor-generator control unit 300 controls the motor-generator 310 so that the actual torque it generates matches the required torque set based on the amount of operation of the accelerator pedal 30, etc. In regenerative power generation mode, the motor-generator control unit 300 controls the absorption torque in the motor-generator 310 according to the required braking force commanded by the brake control unit 100.
[0027] The accelerator pedal 30 shown in Figure 2 is a foot-operated control unit (the pedal of the pedal-type control device of the present invention) used by the driver to operate the accelerator and brake. The accelerator pedal 30 includes a bracket 31, a lever portion 32, a tread surface portion 33, and the like. The bracket 31 is a base that supports the lever portion 32 so that it can rotate around a rotation axis along the vehicle width direction. The bracket 31 has a spring (not shown) that biases the lever portion 32 in the restoring direction (towards the initial position). The bracket 31 is attached to the toe board T, which is a bulkhead located at the front of the passenger compartment. The lever portion 32 is a member that protrudes downward and diagonally backward from the bracket 31. The tread portion 33 is located at the tip of the lever portion 32 (the end opposite to the bracket 31 side) and is the part that comes into contact with the sole of the rider's foot.
[0028] As shown in Figure 2, the tread portion 33 is capable of swinging in the front-rear direction around the pivot point on the bracket 31 side of the lever portion 32. A neutral position P1 is set between the initial position P0, where the tread surface 33 is not pressed against the occupant's foot, and the fully open position P2, where the tread surface 33 is pressed down by the occupant's foot until it hits the stopper. The accelerator pedal 30 is designed to perform accelerator operation using the range from the neutral position P1 to the fully open position P2, and brake operation using the range from the neutral position P1 to the initial position P0. The braking force (deceleration G) due to regenerative braking increases in proportion to the amount of displacement (return) from the neutral position P1 to the initial position P0.
[0029] The motor-generator control unit 300 is connected to the accelerator pedal sensor 301. The accelerator pedal sensor 301 has an encoder that detects the rotational angle position of the lever portion 32 of the accelerator pedal 30. The accelerator pedal sensor 301 is located on the bracket 31. The motor-generator control unit 300 detects the amount of forward movement (pressure) of the tread surface 33 from its initial position based on the output of the accelerator pedal sensor 301. The value detected by the accelerator pedal sensor 301 is transmitted to the brake control unit 100.
[0030] The power steering control unit 400 comprehensively controls an electric power steering system that provides assist force in response to the driver's steering input and steering force during automatic steering to a steering system (not shown) that steers the steering wheels (typically the front wheels) of the vehicle 1. The power steering control unit 400 is connected to a steering angle sensor 410, a torque sensor 420, a motor 430, and other components.
[0031] The steering angle sensor 410 is a sensor (steering angle detection unit) that detects the steering angle in the steering system. The torque sensor 420 is a sensor that detects the torque applied to the steering shaft to which a steering wheel (not shown) is connected, which is operated by the driver. The power steering control unit 400 controls the assist force according to the torque detected by the torque sensor 420. Motor 430 is an electric actuator that provides assist force and steering force to the steering system and generates rack thrust. The output of the motor 430 is controlled by the power steering control unit 400.
[0032] The vibrator control unit 500 is an excitation control unit that supplies a drive current and voltage having a predetermined excitation waveform to the vibrator 501. The vibrator 501 is an excitation unit that excites the tread surface 33 of the accelerator pedal 30, etc. The oscillator 501 can, for example, have a configuration that includes a voice coil and a diaphragm that generate vibrations in response to fluctuations in the supplied voltage. For example, a small speaker can be used as the transducer 501. The transducer 501 is attached to the bracket 31 of the accelerator pedal 30, for example, as shown in Figure 2. The vibrations from the transducer 501 are transmitted sequentially through the bracket 31, the lever portion 32, and the tread portion 33 to the driver's foot.
[0033] Figure 3 is a schematic diagram showing the configuration of the oscillator control unit in the embodiment. The transducer control unit 500 includes a waveform generation unit 510, a first gain adjustment unit 520, a second gain adjustment unit 530, a road surface vibration monitoring unit 540, a vibration amplitude calculation unit 550, a third gain adjustment unit 560, and the like.
[0034] The waveform generation unit 510 generates the fundamental wave of the excitation waveform (without adjusting the gain, etc.), which is the voltage waveform of the drive power of the oscillator 501. Figure 4 is a schematic diagram showing an example of the excitation waveform in the embodiment. In Figure 4, the horizontal axis represents time, and the vertical axis represents voltage. As shown in Figure 4, the excitation waveform can be a square wave, for example, but is not limited to this and may be other waveforms.
[0035] In one embodiment, the frequency of the excitation waveform can be set to have a dominant frequency in the range of 100 to 300 Hz, for example. In this specification, the dominant frequency refers to a frequency whose amplitude is particularly large compared to the amplitudes of other frequencies. Generally, such a dominant frequency often coincides with the frequency with the largest amplitude among several eigenvalues (natural frequencies). The reason is explained below.
[0036] The driver's foot, which touches the tread surface 33, has sensory receptors (tactile sensors) such as Merkel cells, Meissner corpuscles, and Pacinian corpuscles that acquire tactile sensations (skin sensation). Figure 5 schematically shows the timing of electrical pulses emitted by receptors when skin comes into contact with an object. In Figure 5, the horizontal axis represents time, and the vertical axis, from top to bottom, represents pressure and the electrical pulse generation state of Merkel cells, Meissner corpuscles, and Pacinian corpuscles.
[0037] Merkel cells respond relatively slowly and correspond to the DC component. Meissner bodies correspond to situations where a rate of change (velocity) of contact pressure is occurring. Since Meissner bodies always react when moving at high speeds, if a noise signal with a high sensitivity to Meissner bodies is used, it is thought that the driver will be more likely to perceive it as vibration. Pacinian corpuscles respond to moments of transient change and are considered to be the most sensitive of these receptors. Pacinian corpuscles are thought to be the dominant receptors that drivers use to sense the reaction force of micromanipulation.
[0038] Figure 6 shows the sensitivity distribution of Pacinian and Meissner corpuscles with respect to frequency. In Figure 6, the horizontal axis represents frequency, and the vertical axis represents amplitude above the threshold; a smaller value indicates better sensitivity. As shown in Figure 6, Pacinian bodies exhibit good sensitivity in the region around 100 to 300 Hz; therefore, in this embodiment, an excitation waveform having a dominant frequency within the 100 to 300 Hz frequency band is used. Furthermore, by adding components in the frequency band of 10 to 50 Hz to the excitation waveform, it is possible to obtain an effect that stimulates Meissner corpuscles.
[0039] The first gain adjustment unit 520 performs the first gain adjustment on the excitation waveform, as described below. The first gain adjustment involves changing the gain of the excitation waveform in accordance with the change in vehicle deceleration G (change in braking force due to regenerative braking) caused by the regenerative braking system in response to the release operation of the accelerator pedal 30. The vehicle deceleration G can be determined, for example, from the output of the vehicle's longitudinal acceleration sensors or from the target braking force of the regenerative braking system set by the brake control unit 100. Figure 7 is a schematic diagram showing an example of gain adjustment in the first gain adjustment section. In Figure 7, the horizontal axis represents the amount of regenerative braking or acceleration (deceleration G) in the vehicle's deceleration direction, and the vertical axis represents the gain multiplied by the excitation waveform. The gain can be configured to increase, for example, in response to an increase in the amount of regeneration or deceleration G. In particular, when the gain is adjusted according to the amount of regeneration, the change in the amount of regeneration or its indicated value occurs earlier than the change in vehicle behavior, making it easier for the driver to anticipate the generation of braking force due to regenerative braking, which leads to easier operation. Furthermore, if the regenerative braking amount or deceleration G is zero, the gain becomes zero, and excitation by the oscillator 501 is stopped.
[0040] The second gain adjustment unit 530 performs a second gain adjustment on the excitation waveform after the first gain adjustment, as described below. The second gain adjustment adjusts the gain according to the operating speed of the accelerator pedal 30 in both the return and depression directions. The operating speed of the accelerator pedal 30 (the angular velocity of rotation of the pedal surface 33) can be determined by the time derivative of the amount of operation (depression amount) of the accelerator pedal 30 detected by the accelerator pedal sensor 301.
[0041] Figure 8 is a schematic diagram showing an example of gain adjustment in the second gain adjustment section. In Figure 8, the horizontal axis represents the pedal operating speed (for example, the angular velocity of the tread surface 33), and the vertical axis represents the gain multiplied by the excitation waveform. On the horizontal axis, the left side represents the operating speed in the return direction, and the right side represents the operating speed in the stepping direction. The absolute value of the gain can be configured to increase, for example, in accordance with an increase in the absolute value of the pedal operation speed. Here, the rate of increase of the absolute value of the gain with respect to the absolute value of the pedal operation speed is set to be larger in the region where the pedal operation speed is small compared to the region where the absolute value of the operation speed is large, and to gradually decrease as the absolute value of the pedal operation speed increases. Furthermore, when the absolute values of the operating speeds are the same, the absolute value of the gain is set to be greater on the return side than on the push side.
[0042] The road surface vibration monitoring unit 540 has the function of monitoring the output of the acceleration sensor 102 and retaining its history over a predetermined period of time. Figure 9 is a schematic diagram showing an example of the output history of an accelerometer. In Figure 9, the horizontal axis represents time, and the vertical axis represents the detected value of the acceleration sensor 102 (vertical acceleration of the unsprung mass). Data regarding the output history of the acceleration sensor 102 is provided to the vibration amplitude calculation unit 550.
[0043] The vibration amplitude calculation unit 550 applies a bandpass filter to the output of the acceleration sensor 102 provided by the road surface vibration monitoring unit 540 to extract components in a specific frequency range, and then calculates the vibration amplitude in that frequency range. Figure 10 schematically shows the method for calculating vibration amplitude in the vibration amplitude calculation unit. In Figure 10, the horizontal axis represents frequency, and the vertical axis represents the detected value from the acceleration sensor 102. A bandpass filter can be configured to extract a portion of the frequency band (for example, around 250 Hz) that is included in the 100 to 300 Hz band. The vibration amplitude A in the extracted frequency band (for example, the average value of the frequency band) is provided to the third gain adjustment unit 560.
[0044] The third gain adjustment unit 560 performs a third gain adjustment on the noise signal after the second gain adjustment, as described below. The third gain adjustment unit 560 performs a third gain adjustment based on the outputs of the road surface vibration monitoring unit 540 and the vibration amplitude calculation unit 550.
[0045] Figure 11 is a schematic diagram showing an example of gain adjustment in the third gain adjustment section. In Figure 11, the horizontal axis represents the torque amplitude calculated by the vibration amplitude calculation unit 550, and the vertical axis represents the gain multiplied by the excitation waveform. As shown in Figure 11, the third gain adjustment unit 560 increases the gain in response to an increase in the vibration amplitude from the road surface. The oscillator 501 is driven based on the excitation waveform after the excitation waveform generated by the waveform generation unit 510 has undergone the first to third gain adjustments described above. In the third gain adjustment unit 560, if the excitation amplitude added from the vibrator 501 is ΔA and the vibration amplitude from the road surface obtained from the vibration amplitude calculation unit 550 is A, then ΔA / A can be considered to be the Weber ratio W. Therefore, by adjusting the gain so that the Weber ratio W becomes a predetermined value, it is believed that a stable effect can be obtained according to the Weber-Fechner law.
[0046] According to the embodiments described above, the following effects can be obtained. (1) In response to the release movement of the accelerator pedal 30, the accelerator pedal 30 is vibrated in a frequency band in which the sensitivity of Pacinian corpuscles and Meissner corpuscles, which are receptors that control skin sensation, is good. This stimulates these receptors, making it easier for the driver to feel the pressure received from the soles of their feet. As a result, even in the return direction operation, where the driver usually doesn't feel much resistance from the accelerator pedal 30, the spatial resolution in which the driver perceives the amount of movement of the pedal surface 33 is improved, enabling more precise pedal operation. This improves the ease of driving and smoothness of the vehicle 1. (2) By increasing the amplitude of the excitation waveform in accordance with the increasing operating speed of the accelerator pedal 30, the driver's ability to feel the reaction force when releasing the pedal can be effectively improved. In particular, when the operating speed is fast, increasing the excitation amplitude emphasizes the feeling of reaction force (pressure), allowing the driver to feel a change in accordance with the operating speed, and this can act as a damping term. (3) The accelerator pedal 30 has a function that performs gentle braking by regenerative braking when released, so even when braking is performed with a release operation which is difficult to feel in relation to the pressing operation, the spatial resolution of the occupant's pedal operation amount is improved and precise braking operation is possible. Furthermore, in a so-called one-pedal type accelerator pedal 30 in which both acceleration and braking are performed with a single pedal, it is possible to suppress the problem of braking becoming difficult in relation to acceleration, which would impair the smoothness of driving. (4) By increasing the amplitude of the excitation waveform in response to an increase in the amplitude of vibration input from the road surface, the above-mentioned effects can be ensured even when vibrations transmitted from the road surface increase due to, for example, a rough road surface or tire pattern shape.
[0047] (modified version) The present invention is not limited to the embodiments described above, and various modifications and changes are possible, all of which fall within the technical scope of the present invention. (1) The pedal-type operating device, the functions controlled by it, and the configuration of the vehicle are not limited to the embodiments described above and can be modified as appropriate. For example, the present invention can be applied to engine-electric hybrid vehicles (HEVs) and vehicles that use only an internal combustion engine as a power source for driving. For example, the present invention can also be applied to accelerator pedals that perform only acceleration operations, and brake pedals that perform only braking operations. Even in these cases, the precision of the return operation of the accelerator pedal and the return operation of the brake pedal can be improved. (2) In this embodiment, vibrations from the road surface are detected based on the acceleration of the unsprung portion of the suspension device, but the method for detecting vibrations from the road surface is not limited to this and can be changed as appropriate. For example, a vibration pickup may be installed in the brake fluid piping (brake line) connected to the wheel cylinder located in the unsprung portion. Alternatively, vibrations from the road surface may be detected based on the output of the torque sensor of the power steering system. (3) In this embodiment, a square wave is used as the excitation waveform as an example, but it is not limited to this, and other waveforms of noise signals such as sine waves, triangular waves, or random waves may be used. Also, the gain adjustment method is not limited to the configuration of this embodiment and can be changed as appropriate. (4) The specific configuration of the vibrator (excitation unit), the principle of excitation, and the installation location are not limited to the embodiment and can be modified as appropriate. (5) The configuration of the accelerator pedal (pedal-type operating device) in the embodiment is an example, and the present invention can be applied to other forms of pedal-type operating devices. For example, the present invention can be applied to a so-called organ-type pedal-type operating device in which a pivot shaft for rotating the tread is provided below the tread. [Explanation of Symbols]
[0048] 1 vehicle 100 Brake control unit 101 Vehicle speed sensor 102 Acceleration sensor 110 Brake pedal sensor 120 Reaction force generating device 130 Master cylinder 200 Hydraulic Control Unit 210 Wheel Cylinder 300 Motor Generator Control Unit 310 Motor Generator 30 Accelerator pedal 31 Bracket 32 Lever section 33 Tread section 400 Power steering control unit 301 Accelerator pedal sensor 410 Steering angle sensor 420 Torque sensor 430 Motor 500 Transducer control unit 501 Transducer 510 Waveform generation unit 520 First gain adjustment unit 530 Second gain adjustment unit 540 Road surface vibration monitor unit 550 Vibration amplitude calculation unit 560 Third gain adjustment unit
Claims
1. A pedal-operated control system in which the operation of the vehicle is performed by a foot pedal, A vibration unit that vibrates the pedal, The operation detection unit detects the operation of the pedal, In response to the pedal's return movement detected by the motion detection unit, the vibration control unit vibrates the pedal with at least one vibration waveform from a frequency band of 10 to 50 Hz and a frequency band of 100 to 300 Hz. Equipped with, The aforementioned pedal is A function that performs braking operations that increase braking force according to the amount of movement in the return direction, A function that performs a driving force operation that increases the driving force according to the amount of operation in the direction of pressing down in the region within the range of motion where the aforementioned braking force is not generated, It has, The vibration control unit increases the amplitude of the vibration waveform in accordance with the increase in braking force corresponding to the braking operation. A pedal-operated control device characterized by the following.
2. The motion detection unit detects the operating speed of the pedal, The vibration control unit increases the amplitude of the vibration waveform in accordance with the increase in the operating speed. A pedal-operated device according to claim 1, characterized by the following:
3. It is equipped with a vibration input detection unit that detects vibration input from the road surface, The vibration control unit increases the amplitude of the vibration waveform in response to an increase in the amplitude of the vibration input. A pedal-operated device according to claim 1 or claim 2, characterized by the above.
4. A pedal-operated control system in which the operation of the vehicle is performed by a foot pedal, A vibration unit that vibrates the pedal, The operation detection unit detects the operation of the pedal, The vibration control unit, in response to the pedal return movement detected by the motion detection unit, causes the vibration unit to vibrate the pedal with at least one of the vibration waveforms in the frequency band of 10 to 50 Hz and the frequency band of 100 to 300 Hz, A vibration input detection unit that detects vibration input from the road surface and Equipped with, The motion detection unit detects the operating speed of the pedal, The vibration control unit, The amplitude of the excitation waveform is increased in accordance with the increase in the operating speed, The amplitude of the excitation waveform is increased in accordance with the increase in the amplitude of the vibration input. A pedal-operated control device characterized by the following.
5. A pedal-operated control system in which the operation of the vehicle is performed by a foot pedal, A vibration unit that vibrates the pedal, The operation detection unit detects the operation of the pedal, The vibration control unit, in response to the pedal return movement detected by the motion detection unit, causes the vibration unit to vibrate the pedal with at least one of the vibration waveforms in the frequency band of 10 to 50 Hz and the frequency band of 100 to 300 Hz, A vibration input detection unit that detects vibration input from the road surface and Equipped with, The pedal has a function to perform a braking operation that increases the braking force according to the amount of movement in the return direction. The vibration control unit, The amplitude of the excitation waveform is increased in accordance with the increase in braking force corresponding to the braking operation, The amplitude of the excitation waveform is increased in accordance with the increase in the amplitude of the vibration input. A pedal-operated control device characterized by the following.
6. A pedal-operated control system in which the operation of the vehicle is performed by a foot pedal, A vibration unit that vibrates the pedal, The operation detection unit detects the operation of the pedal, In response to the pedal's return movement detected by the motion detection unit, the vibration control unit vibrates the pedal with at least one vibration waveform from a frequency band of 10 to 50 Hz and a frequency band of 100 to 300 Hz. Equipped with, The pedal has a function to perform a braking operation that increases the braking force according to the amount of movement in the return direction. The vibration control unit causes the pedal to continuously vibrate the vibration unit while the braking force is being generated by the pedal's return movement. A pedal-operated control device characterized by the following.