Pedal feeling-adjustable pedal feeling simulator and control method thereof
By using a combination of control unit, simulation cylinder, piston and elastic parts in the pedal sense simulator, the use of gas pressure and elastic parts to provide a pedal sense, and replenish gas through the atmosphere in the case of a fault, the existing pedal sense simulator is solved by using the combination of control units, simulation cylinder, piston and elastic parts to provide a pedal sense simulator. The problem of being stepped on improves safety and structural simplicity.
Patent Information
- Application Number
- CN202310727933.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-19
- Publication Date
- 2024-12-20
AI Technical Summary
The existing pedal sense simulator cannot be stepped on in the event of a failure, resulting in poor driver experience and increased safety risks, and the existing technology mechanism is complex and vulnerable to damage.
Design a pedal sense simulator with adjustable pedal sense, using control unit, simulation cylinder, piston and elastic member, to adjust the pedal sense through regulating valves and pressure sensors, and to provide reverse thrust with gas pressure and elastic member to ensure the pedal The pedal is available through atmospheric replenishment gas when the regulating valve is damaged.
It realizes flexible adjustment of pedal sense and fault tolerance, improves the safety and structural simplicity of the pedal sense simulator, and ensures that the driver can have a controllable pedal sense in different situations.
Smart Images
Figure CN119160141A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of pedal feeling simulators, and in particular to a pedal feeling simulator with adjustable pedal feeling and a control method thereof. Background Art
[0002] With the development of automobile technology and the current trend of energy conservation and environmental protection, new energy vehicles are developing in depth, and the wire control brake technology with electronic hydraulic brake and electronic mechanical brake as the main forms has gradually been developed and applied. With the popularization of wire control brake system in new energy vehicles, the driver's braking intention is no longer transmitted to the brake execution system mechanically but electronically, which requires the design of brake pedal feel simulator to provide the driver with reliable braking force feedback to enhance the driver's controllable sense of braking results.
[0003] There are currently three types of pedal feel simulators that are used. These three types are the most basic forms of pedal simulators, and two or even three types can exist in the same pedal feel simulator. One of these three types is to use springs and damping to simulate pedal feel, but since springs and damping cannot be adjusted, the actual adjustment range of different pedal feels is greatly limited; the second is to use motors and deceleration mechanisms to dynamically adjust the size of the pedal feel assistance to achieve different pedal feels, but the mechanism and control logic are complex, and system failure will cause the driver's pedal feel to change dramatically. In extreme cases, the simulator mechanical mechanism will get stuck and the brake pedal cannot be stepped on, which seriously affects the user experience and even causes driving safety issues; the third is to adjust the hydraulic pressure to give the user a different pedal feel, but this method has the same defects as the second method. If the regulating valve is damaged, the liquid cannot be discharged, which will cause the brake pedal to be unable to be stepped on. Summary of the invention
[0004] One of the purposes of the present invention is to provide a pedal feel simulator with adjustable pedal feel to solve the problem in the prior art that the pedal feel simulator fails and cannot be stepped on; the second purpose is to provide a control method for the pedal feel simulator.
[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:
[0006] A pedal feel simulator with adjustable pedal feel comprises a control unit, a simulation cylinder, a piston and an elastic member both installed in the simulation cylinder, wherein the elastic member is located between the piston and the bottom of the simulation cylinder, and the movement of the piston toward the bottom of the simulation cylinder will compress the elastic member; a pressure sensor electrically connected to the control unit is installed in the simulation cylinder; the simulation cylinder is connected to an intake pipeline and an exhaust pipeline, a one-way valve is provided on the intake pipeline, and a regulating valve electrically connected to the control unit is provided on the exhaust pipeline.
[0007] According to the above technical means, the pedal push rod of the brake pedal is connected to the piston, and the gas enters the simulation cylinder through the intake pipe. When the driver steps on the brake pedal, the brake pedal pushes the pedal push rod to push the piston to the bottom of the simulation cylinder. During the movement of the piston, the elastic member will provide reverse thrust to the piston, and the piston will also compress the gas, and the gas will flow out of the simulation cylinder from the exhaust pipe and through the regulating valve. That is, during the movement of the piston, the pedal feel is provided by the elastic member and the gas pressure. Among them, the control unit can be based on the needs of the driver, such as the driver selects a mode with different pedal feels. The control unit allows the regulating valve to be at different openings according to different pedal feels. The larger the opening of the regulating valve, the faster the gas flow rate and the smaller the gas resistance; the smaller the opening, the slower the gas flow rate and the greater the gas pressure. The opening size of the regulating valve is positively correlated with the current size received by the regulating valve. The larger the control current output to the regulating valve, the larger the opening of the regulating valve. When the control current is 0, the regulating valve is closed; when the control current reaches the maximum value, the opening of the regulating valve reaches the maximum. The opening change of the regulating valve is combined with the data feedback of the pressure sensor. The pressure sensor detects the actual pressure in the simulated cylinder, and different pedal feelings give different pressures to the piston. The elastic force of the elastic part cannot be adjusted, so only the gas pressure can be adjusted. Different pedal feelings mean that there are one or more different and set target pressures of the gas, and the control unit controls the opening of the regulating valve according to the difference between the target pressure and the actual pressure.
[0008] When the driver releases the brake pedal, the piston resets under the action of the elastic member. At this time, the air pressure in the simulation cylinder drops. When the air pressure in the simulation cylinder is less than a certain threshold, the gas will push the one-way valve to open and enter the simulation cylinder. Specifically, the gas can be air, that is, when the air pressure in the simulation cylinder is lower than the atmospheric pressure, air will enter the simulation cylinder.
[0009] Gas is compressible. Even if the regulating valve is damaged and cannot be opened, the piston can still compress the gas in the simulation cylinder so that the brake pedal can still be stepped on. At this time, the gas in the simulation cylinder reaches the maximum air pressure, and after adding the elastic force of the elastic part, it is the maximum pedal force required by the driver, and the driver still has a controllable brake pedal feel.
[0010] Furthermore, at least two stroke sensors for sensing the piston stroke are installed in the simulation cylinder, and the stroke sensors are electrically connected to the control unit.
[0011] According to the above-mentioned technical means, the stroke sensor can measure the stroke of the piston in the simulated cylinder in real time. The control unit controls the opening of the regulating valve according to the stroke of the piston and the actual pressure of the pressure sensor, so that the regulating valve is kept at the required opening, so that when the piston reaches different strokes, there are corresponding pressure changes to achieve the set target pressure.
[0012] Furthermore, the elastic member has two parts, namely a first elastic part and a second elastic part. One end of the first elastic part abuts against the bottom of the simulation cylinder, and the other end abuts against the piston. One end of the second elastic part abuts against the bottom of the simulation cylinder, and the other end is a free end and is at a distance from the piston.
[0013] According to the above-mentioned technical means, the movement of the piston can be divided into two strokes. In the first stroke, the piston pushes the first elastic part to deform, and the first elastic part and the gas pressure give the piston a first-level reverse thrust. When the driver continues to step on the brake pedal, the piston continues to move forward until it reaches the second stroke. The piston compresses the first elastic part and the second elastic part at the same time. At this time, the first elastic part, the second elastic part and the gas pressure give the piston a second-level reverse thrust. By setting the first elastic part and the second elastic part, the piston is subjected to more variable reverse thrusts, which makes the adjustable range of the pedal feel larger, and the driver can more flexibly choose the pedal feel he wants. More elastic parts can be set and are not limited to two.
[0014] Furthermore, a limit base is provided at the bottom of the simulation cylinder, and the simulation cylinder is provided with a contact switch for detecting contact between the piston and the limit base, and the contact switch is electrically connected to the control unit.
[0015] According to the above-mentioned technical means, the limit base can limit the maximum stroke of the piston. When the piston contacts the limit base, the contact switch will be triggered. The contact switch will send a maximum braking capacity requirement signal to the control unit. The braking force of the car reaches its maximum at this time. The piston cannot and does not need to continue moving forward, thereby avoiding excessive compression of the first elastic member and the second elastic member.
[0016] Furthermore, the limiting base is provided with an elastic portion abutting against the piston.
[0017] According to the above technical means, the piston abuts against the elastic part of the limit base and compresses the elastic part. When the piston contacts the limit base, the contact switch will be triggered, and the contact switch will send a maximum braking capacity requirement signal to the control unit, and the braking force of the car will reach the maximum at this time. The role of the elastic part is to buffer the collision between the piston and the limit base, so that the piston still has a small amount of moving space, and the elastic part will also give the piston a reverse thrust, so that the pedal feel continues to change so that the driver feels that the maximum travel of the brake pedal has been reached.
[0018] Furthermore, the first elastic member is located between the limiting base and the simulation cylinder; the limiting base is provided with a first accommodating cavity, and one end of the second elastic member is located in the first accommodating cavity.
[0019] According to the above-mentioned technical means, the limiting base separates the first elastic member and the second elastic member so that the operations of the first elastic member and the second elastic member do not interfere with each other. At the same time, the limiting base restricts the first elastic member, and the first accommodating chamber restricts the second elastic member, so that the first elastic member and the second elastic member will not have radial displacement at one end close to the bottom of the simulation cylinder, and the elastic force output by the first elastic member and the second elastic member is more accurate.
[0020] Furthermore, the piston is provided with a second accommodating cavity, the free end of the second elastic member is located in the second accommodating cavity and there is a distance between the free end of the second elastic member and the inner bottom surface of the second accommodating cavity; the piston is provided with a limiting groove for accommodating the first elastic member.
[0021] According to the above-mentioned technical means, the second accommodating chamber restricts the position of the free end of the second elastic member, and the limiting groove restricts the position of the end of the first elastic member away from the limiting base, so that the first elastic member and the second elastic member will not be radially offset at the end close to the piston, and the elastic force output by the first elastic member and the second elastic member is more accurate.
[0022] Furthermore, a sealing ring abutting against an inner wall of the simulation cylinder is disposed on the outer surface of the piston, and a limiting ring for limiting the piston from leaving the simulation cylinder is disposed at one end of the simulation cylinder away from the bottom thereof.
[0023] According to the above technical means, the sealing ring forms a closed space between the simulation cylinder and the piston to prevent gas leakage and improve the accuracy of air pressure detection. After the piston is reset to the limit position under the elastic force of the elastic member, it is restricted by the limit ring so that the piston cannot leave the simulation cylinder.
[0024] A control method for a pedal feel simulator with adjustable pedal feel is as follows:
[0025] Set multiple pedal feel modes and set the corresponding pedal force in different modes;
[0026] Selecting one of the pedal feel modes, the control unit collects data from the travel sensor and the pressure sensor;
[0027] When the pedal is pressed, the states of the stroke sensor, the pressure sensor and the regulating valve are detected and determined; if there is no abnormality in the stroke sensor, the regulating valve and the pressure sensor, the opening of the regulating valve is controlled according to the selected pedal feel mode to provide the set pedal force; if all the stroke sensors are damaged, the regulating valve is closed; if the pressure sensor is abnormal, the regulating valve is kept normally open; if the regulating valve is damaged and the opening cannot be adjusted, the regulating valve is kept normally open.
[0028] According to the above technical means, when using the pedal feel simulator, the corresponding pedal force in different modes is first set, that is, the opening of the regulating valve. When the driver steps on the pedal, the control unit first detects whether there is an abnormality in the stroke sensor, pressure sensor and regulating valve. If there is an abnormality, the regulating valve is kept in a normally open state or a normally closed state according to the different abnormal situations. When the pressure sensor is damaged and the regulating valve cannot adjust the opening, the function of the regulating valve is lost. At this time, the regulating valve is kept in a normally open state, the pedal force is in a minimum state, that is, the pedal feel is the weakest, and the stroke of the piston is detected by the stroke sensor to continue to provide the driver with an acceptable and safe pedal force. When the stroke sensor is damaged, the stroke of the piston cannot be known at this time, then the regulating valve is closed, the pedal force is in a maximum state, that is, the pedal feel is the strongest, and then the stroke of the piston is judged by the pressure data of the pressure sensor.
[0029] Furthermore, the pedal feel mode includes a comfort mode, a sports mode and a custom mode; in the comfort mode, the regulating valve remains normally open; in the sports mode, the regulating valve remains normally closed; in the custom mode, the pedal force is set and the actual pressure is obtained through the pressure sensor, and the control unit controls the opening of the regulating valve according to the target pressure so that the actual pressure is consistent with the target pressure.
[0030] According to the above technical means, the pedal feel mode includes but is not limited to the comfort mode, sports mode and custom mode. In the comfort mode, the control current of the regulating valve is 0, the regulating valve is in a normally open state, and the simulated cylinder does not form any gas pressure on the piston. The relationship curve between the pedal force and the stroke is: k1*(L1+L2+L3)+k2*(L2+L3)+k3*L3; in the sports mode, the control current of the regulating valve is the maximum value, the regulating valve is in a normally closed state, and the simulated cylinder gas pressure on the piston is P*S. The relationship curve between the pedal force and the stroke is:
[0031] k1*(L1+L2+L3)+k2*(L2+L3)+k3*L3+P*S, where P increases with the movement of the piston. The custom mode can set the pressure of the simulated cylinder on the piston to a constant value in a certain stroke section or the entire stroke section, that is, the target pressure. The control unit can change the actual pressure in the simulated cylinder as the opening of the regulating valve changes according to the difference between the target pressure and the actual pressure, so that the actual pressure remains consistent with the target pressure during continuous adjustment.
[0032] Furthermore, in the custom mode, a mapping relationship between the piston position and the corresponding target pressure is established according to the set pedal force, the control unit detects the piston stroke through the stroke sensor, obtains the target pressure according to the mapping relationship and obtains the actual pressure through the pressure sensor, and the control unit controls the opening of the regulating valve according to the difference between the target pressure and the actual pressure.
[0033] According to the above technical means, in the custom mode, the pressure of the simulated cylinder on the piston is set to a constant value in a certain stroke section or the entire stroke section, that is, the piston has different target pressures at different strokes. If the entire stroke is set to one target pressure, then the mapping relationship between the piston position and the target pressure is unique, and different stroke sections have different target pressures, so there are multiple mapping relationships between the piston position and the target pressure. The control unit obtains the position of the piston through the stroke sensor at all times to obtain the target pressure and the actual pressure through the pressure sensor, and then changes the opening of the regulating valve according to the difference between the two, so that the actual pressure at all times can be equal to or close to the target pressure.
[0034] Furthermore, in the custom mode, the specific process of pedal force adjustment is as follows:
[0035] Step 1: the stroke sensor detects the position of the piston and the pressure sensor detects the actual pressure of the gas in the simulated cylinder;
[0036] Step 2: The control unit obtains the target pressure according to the piston position and the mapping relationship, and compares the target pressure with the actual pressure; if the actual pressure is greater than the target pressure, step 3 is executed; if the actual pressure is less than the target pressure, step 4 is executed; if the target pressure is consistent with the actual pressure, step 5 is executed;
[0037] Step 3: The control unit increases the opening of the regulating valve and then executes step 5;
[0038] Step 4: The control unit reduces the opening of the regulating valve and then executes step 5;
[0039] Step 5: Repeat steps 1 and 2.
[0040] According to the above-mentioned technical means, the above-mentioned process is continuously executed in a cycle during the movement of the piston, so that the opening of the regulating valve is continuously changed when the actual pressure is inconsistent with the target pressure, so that the actual pressure can be equal to or close to the target pressure as much as possible when the piston moves to different positions and at each moment. Since the stroke change of the piston actually goes through a certain period of time, the above-mentioned steps can be executed multiple times within this period of time to adjust the actual pressure.
[0041] Furthermore, an increase value for increasing the opening of the regulating valve and a decrease value for decreasing the opening of the regulating valve are set; in step three, the control unit increases the opening of the regulating valve according to the increase value; in step four, the control unit decreases the opening of the regulating valve according to the decrease value.
[0042] According to the above-mentioned technical means, by setting the amplitude of each increase or decrease in the opening of the control valve, the opening of the control valve can be changed more standardized each time. Increasing the opening and decreasing the opening have their own corresponding amplitudes, and the same change amplitude can be executed each time. This makes it more convenient to change the opening of the control valve and reduces the amount of calculation of the control unit.
[0043] Beneficial effects of the present invention:
[0044] (1) The pedal feel can be adjusted by changing the opening of the regulating valve. Even if the regulating valve fails, the piston can still compress the gas in the simulated cylinder so that the pedal can be pressed, thereby improving the safety of the pedal feel simulator.
[0045] (2) The pedal feel simulator only requires a gas circuit, in which the gas supply can be supplemented by the atmosphere. Compared with hydraulics which require a hydraulic tank, a motor, and a reduction mechanism, the structure of this pedal feel simulator is simpler.
[0046] (3) The pedal feel simulator can adjust the gas pressure in the simulation cylinder according to different modes. By simply controlling the opening of the regulating valve, the gas pressure in the simulation cylinder can be quickly changed to create different pedal force changes, allowing the driver to more flexibly adjust the pedal feel he wants. BRIEF DESCRIPTION OF THE DRAWINGS
[0047] Figure 1 It is a structural schematic diagram of a pedal feel simulator with adjustable pedal feel of the present invention;
[0048] Figure 2 A flow chart of a control method of a pedal feel simulator with adjustable pedal feel according to the present invention;
[0049] Figure 3 is a curve showing the relationship between the piston stroke and the pedal force of the present invention;
[0050] Figure 4 The flowchart of the pedal force adjustment of the pedal feel simulator of the present invention in the custom mode.
[0051] Among them, 1-simulation cylinder; 2-piston; 201-second accommodating chamber; 202-sealing ring; 3-elastic part; 301-first elastic part; 302-second elastic part; 4-control unit; 5-pressure sensor; 6-intake pipe; 7-exhaust pipe; 8-one-way valve; 9-regulating valve; 10-stroke sensor; 11-limiting base; 1101-first accommodating chamber; 12-contact switch; 13-elastic part; 14-limiting ring; 15-pedal push rod. DETAILED DESCRIPTION
[0052] The following will describe the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention, not for limiting the scope of protection of the present invention.
[0053] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.
[0054] This embodiment provides a pedal feel simulator with adjustable pedal feel, such as Figure 1 As shown, it includes a control unit 4, a simulation cylinder 1, a piston 2 and an elastic member 3 both installed in the simulation cylinder 1, the elastic member 3 is located between the piston 2 and the bottom of the simulation cylinder 1, and the piston 2 moves toward the bottom of the simulation cylinder 1 to compress the elastic member 3; a pressure sensor 5 electrically connected to the control unit 4 is installed in the simulation cylinder 1; the simulation cylinder 1 is connected to an intake pipe 6 and an exhaust pipe 7, a one-way valve 8 is provided on the intake pipe 6, and a regulating valve 9 electrically connected to the control unit 4 is provided on the exhaust pipe 7. The intake end of the intake pipe 6 is connected to the outside atmosphere. The control unit 4 is an ECU (Electronic Control Unit) of the car.
[0055] Specifically, two stroke sensors 10 for sensing the stroke of the piston 2 are installed in the simulation cylinder 1, and the stroke sensors 10 are electrically connected to the control unit 4. The stroke sensors 10 of this embodiment are arranged on the inner wall of the simulation cylinder 1, and the two stroke sensors 10 have the same function and detection stroke. Even if one of the stroke sensors 10 is damaged, the other stroke sensor 10 still works, which will not affect the operation of the pedal feel simulator, and is safer to use.
[0056] Furthermore, the elastic member 3 has two parts, namely a first elastic member 301 and a second elastic member 302. One end of the first elastic member 301 abuts against the bottom of the simulation cylinder 1, and the other end abuts against the piston 2. One end of the second elastic member 302 abuts against the bottom of the simulation cylinder 1, and the other end is a free end and is at a distance from the piston 2.
[0057] The pedal push rod 15 of the brake pedal is connected to the piston 2, and the gas enters the simulation cylinder 1 through the intake pipe 6. When the driver steps on the brake pedal, the brake pedal pushes the pedal push rod 15 to push the piston 2 to the bottom of the simulation cylinder 1. When the piston 2 moves, the stroke sensor 10 detects the stroke of the piston 2 in real time and obtains the position of the piston 2. At the same time, when the piston 2 is in the first-stage stroke, the first elastic member 301 will provide a reverse thrust to the piston 2, and the piston 2 will also compress the gas, and the gas will flow out of the simulation cylinder 1 from the exhaust pipe 7 and through the regulating valve 9. That is, during the movement of the piston 2 in the first-stage stroke, the pedal feel is provided by the first elastic member 301 and the gas pressure. When the piston 2 begins to contact the second elastic member 302 and compress the second elastic member 302, the piston 2 enters the second-stage stroke. At this time, the first elastic member 301, the second elastic member 302 and the gas pressure give the piston 2 a reverse thrust.
[0058] During the entire movement of the piston 2, the control unit 4 can adjust the opening of the regulating valve 9 to different degrees according to the needs of the driver, such as when the driver selects a mode with different pedal feelings. The control unit 4 adjusts the opening of the regulating valve 9 to different degrees according to different pedal feelings. The larger the opening of the regulating valve 9, the faster the gas flow rate and the smaller the gas resistance; the smaller the opening, the slower the gas flow rate and the greater the gas pressure. The opening adjustment size of the regulating valve 9 is positively correlated with the current size received by the regulating valve 9. The larger the control current output to the regulating valve 9, the larger the opening of the regulating valve 9. When the control current is 0, the regulating valve 9 is closed; when the control current reaches the maximum value, the opening of the regulating valve 9 reaches the maximum. The change is combined with the data feedback of the pressure sensor 5 and the stroke sensor 10. The pressure sensor 5 detects the actual pressure in the simulated cylinder 1, and the stroke sensor 10 obtains the real-time position of the piston 2. Different pedal feelings give different pressures to the piston 2. The elastic force of the elastic member 3 cannot be adjusted, so only the gas pressure can be adjusted. Different pedal feelings mean that the piston 2 has one or more different and set target pressures of the gas at different positions, and the control unit 4 controls the opening of the regulating valve 9 according to the difference between the target pressure and the actual pressure.
[0059] When the driver releases the brake pedal, the piston 2 is reset under the action of the elastic member 3 , and the air pressure in the simulation cylinder 1 drops. When the air pressure in the simulation cylinder 1 is lower than the atmospheric pressure, air will enter the simulation cylinder 1 .
[0060] The gas is compressible. Even if the regulating valve 9 is damaged and cannot be opened, the piston 2 can still compress the gas in the simulation cylinder 1, so that the brake pedal can still be stepped on. At this time, the gas in the simulation cylinder 1 reaches the maximum air pressure, and after adding the elastic force of the elastic part 3, it is the maximum pedal force required by the driver, and the driver still has a controllable brake pedal feel.
[0061] In this embodiment, the regulating valve 9 is a linear proportional regulating valve 9 , the first elastic member 301 and the second elastic member 302 are both springs, and the travel sensor 10 is a travel switch.
[0062] In this embodiment, a limit base 11 is provided at the bottom of the simulation cylinder 1, and the simulation cylinder 1 is provided with a contact switch 12 for detecting the contact between the piston 2 and the limit base 11. Specifically, the limit base 11 is provided with an elastic part 13 for contacting the piston 2. The contact switch 12 is electrically connected to the control unit 4, and the contact switch 12 is installed on the inner wall of the simulation cylinder 1. In the radial direction of the simulation cylinder 1, the contact switch 12 is flush with the end surface of the elastic part 13 close to the piston 2. The limit base 11 can limit the maximum stroke of the piston 2. When the piston 2 contacts the elastic part 13 of the limit base 11, the contact switch 12 will be triggered. The contact switch 12 will send a maximum braking capacity required signal to the control unit 4. The braking force of the car reaches the maximum at this time, and the piston 2 cannot and does not need to continue to move forward. However, in order to avoid the rigid collision between the piston 2 and the limit base 11, the elastic part 13 buffers the collision between the piston 2 and the limit base 11, and the piston 2 still has a small amount of moving space and the elastic part 13 will also give the piston 2 a reverse thrust. This not only avoids over-compression of the first elastic member 301 and the second elastic member 302, but also allows the pedal feel to continue to change through the elastic force of the elastic portion 13 so that the driver can feel that the maximum travel of the brake pedal has been reached. The elastic portion 13 is an elastic rubber ring.
[0063] In this embodiment, the first elastic member 301 is located between the limiting base 11 and the simulation cylinder 1; the limiting base 11 is provided with a first accommodating chamber 1101, and one end of the second elastic member 302 is located in the first accommodating chamber 1101. The limiting base 11 separates the first elastic member 301 and the second elastic member 302, so that the first elastic member 301 and the second elastic member 302 do not interfere with each other. At the same time, the limiting base 11 limits the first elastic member 301, and the first accommodating chamber 1101 limits the second elastic member 302, so that the first elastic member 301 and the second elastic member 302 close to the bottom of the simulation cylinder 1 will not be radially offset, and the elastic force output by the first elastic member 301 and the second elastic member 302 is more accurate. The piston 2 is provided with a second accommodating chamber 201, and the free end of the second elastic member 302 is located in the second accommodating chamber 201 and there is a distance between the free end and the inner bottom surface of the second accommodating chamber 201; the piston 2 is provided with a limiting groove for accommodating the first elastic member 301. The second accommodating cavity 201 limits the position of the free end of the second elastic member 302, and the limiting groove limits the position of the end of the first elastic member 301 away from the limiting base 11, so that the first elastic member 301 and the second elastic member 302 will not be radially offset at the end close to the piston 2, and the elastic force output by the first elastic member 301 and the second elastic member 302 is more accurate.
[0064] In this embodiment, the outer surface of the piston 2 is provided with a sealing ring 202 that abuts against the inner wall of the simulation cylinder 1, and the end of the simulation cylinder 1 away from its bottom is provided with a limiting ring 14 that limits the piston 2 from leaving the simulation cylinder 1. The sealing ring 202 forms a closed space between the simulation cylinder 1 and the piston 2 to prevent gas leakage and improve the accuracy of air pressure detection. After the piston 2 is reset to the limit position under the elastic force of the elastic member 3, it is limited by the limiting ring 14 so that the piston 2 cannot leave the simulation cylinder 1.
[0065] This embodiment also proposes a control method for a pedal feel simulator with adjustable pedal feel, based on the above-mentioned pedal feel simulator with adjustable pedal feel, including: Figure 2 The following steps are shown:
[0066] Set multiple pedal feel modes and set the corresponding pedal force in different modes;
[0067] Selecting one of the pedal feel modes, the control unit 4 collects data from the travel sensor 10, the pressure sensor 5, the contact switch 12 and the regulating valve 9;
[0068] When the pedal is stepped on, the status of the stroke sensor 10, the pressure sensor 5, the regulating valve 9 and the contact switch 12 are detected and determined; if the stroke sensor 10, the regulating valve 9, the pressure sensor 5 and the contact switch 12 are all normal, the opening of the regulating valve 9 is controlled according to the selected pedal feel mode to provide the set pedal force; if all the stroke sensors 10 are damaged, the regulating valve 9 is closed; if only one stroke sensor 10 is damaged, the opening of the regulating valve 9 is controlled according to the selected pedal feel mode to provide the set pedal force; if the pressure sensor 5 is abnormal, the regulating valve 9 is kept normally open; if the regulating valve 9 is damaged and the opening cannot be adjusted, the regulating valve 9 is kept normally open. If the contact switch 12 is abnormal, the control unit 4 combines the data of the stroke sensor 10 and the pressure sensor 5, and controls the opening of the regulating valve 9 according to the selected pedal feel mode to provide the set pedal force.
[0069] When using the pedal feel simulator, first set the corresponding pedal force in different modes, that is, the opening of the regulating valve 9. When the driver steps on the pedal, the control unit 4 first detects whether there is an abnormality in the stroke sensor 10, the pressure sensor 5 and the regulating valve 9. If there is an abnormality, the regulating valve 9 is kept in a normally open state or a normally closed state according to the different abnormal situations. When the pressure sensor 5 is damaged and the regulating valve 9 cannot adjust the opening, the function of the regulating valve 9 is lost. At this time, the regulating valve 9 is kept in a normally open state, the pedal force is in a minimum state, and the stroke of the piston 2 is detected by the stroke sensor 10, and the driver continues to be provided with an acceptable and safe pedal force. When the stroke sensor 10 is damaged, the stroke of the piston 2 cannot be known at this time, then the regulating valve 9 is closed, the pedal force is in a maximum state, and then the stroke of the piston 2 is judged by the pressure data of the pressure sensor 5.
[0070] In this embodiment, the pedal feel mode includes but is not limited to a comfort mode, a sports mode and a custom mode; in the comfort mode, the regulating valve 9 remains normally open; in the sports mode, the regulating valve 9 remains normally closed; in the custom mode, the pedal force is set and the actual pressure is obtained through the pressure sensor 5, and the control unit 4 controls the opening of the regulating valve 9 according to the target pressure so that the actual pressure is consistent with the target pressure.
[0071] In the comfort mode, the control current of the regulating valve 9 is 0, the regulating valve 9 is in a normally open state, and no gas pressure is formed in the simulated cylinder 1 on the piston 2. The relationship curve between the pedal force and the stroke is as follows: Figure 3 As shown: k1*(L1+L2+L3)+k2*(L2+L3)+k3*L3; in the sports mode, the control current of the regulating valve 9 is the maximum value, the regulating valve 9 is in the normally closed state, the gas pressure in the simulated cylinder 1 on the piston 2 is P*S, and the relationship curve between the pedal force and the stroke is as follows Figure 3As shown: k1*(L1+L2+L3)+k2*(L2+L3)+k3*L3+P*S, where P increases with the movement of the piston 2. Among them, k1 is the elastic coefficient of the first elastic member, L1 is the length of the first-stage stroke, L2 is the length of the second-stage stroke, L3 is the length of the third-stage stroke, k1 is the elastic coefficient of the second elastic member, k3 is the elastic coefficient of the elastic part, P is the gas pressure, and S is the contact area between the piston and the gas. The custom mode can set the pressure of the simulation cylinder 1 on the piston 2 to a constant value in a certain stroke segment or the entire stroke segment, that is, the target pressure. The control unit 4 can change the actual pressure in the simulation cylinder 1 as the opening of the regulating valve 9 changes according to the difference between the target pressure and the actual pressure, so that the actual pressure remains consistent with the target pressure during continuous adjustment. Specifically, in the custom mode, the specific process of pedal force adjustment is as follows: Figure 4 Shown are:
[0072] Preset step: setting an increase value for increasing the opening of the regulating valve 9 and a decrease value for decreasing the opening of the regulating valve 9, wherein the increase value is a maximum value and the decrease value is a constant threshold value;
[0073] Step 1: The stroke sensor 10 detects the position of the piston 2 and the pressure sensor 5 detects the actual pressure of the gas in the simulated cylinder 1;
[0074] Step 2: The control unit 4 obtains the target pressure according to the position of the piston 2 and the mapping relationship, and compares the target pressure with the actual pressure; if the actual pressure is greater than the target pressure, step 3 is executed; if the actual pressure is less than the target pressure, step 4 is executed; if the target pressure is consistent with the actual pressure, step 5 is executed;
[0075] Step 3: The control unit 4 increases the opening of the regulating valve 9 to the maximum value and then executes step 5;
[0076] Step 4: The control unit 4 reduces the opening of the regulating valve 9 by a preset reduction value and then executes step 5;
[0077] Step 5: Repeat steps 1 and 2.
[0078] According to the above steps of the present embodiment, the driver sets a custom mode as an example. The driver wants a larger pedal force in the first stroke, that is, when only the first elastic member 301 is compressed, so the target pressure in the first stroke L1 is set to the first pressure value A. When the first elastic member 301 or the second elastic member 302 is compressed, the driver wants the pedal force to change slightly, and the target pressure in the second stroke L2 is set to the second pressure value B, wherein the second pressure value B is less than the first pressure value A. When the elastic part 13 is compressed, the pedal force required by the driver will not form too much resistance, that is, the target pressure in the third stroke L3 is set to 0. The recommended mapping relationship is that the target pressure corresponding to the piston 2 in the range of the first stroke L1 is the first pressure value A, the target pressure corresponding to the piston 2 in the range of the second stroke L2 is the first pressure value B, and the target pressure of the piston 2 in the third stroke L3 is 0.
[0079] When the driver steps on the pedal, the piston 2 starts to compress the first elastic member 301, and the control unit 4 obtains the position of the piston 2 detected by the stroke sensor 10 and the actual pressure detected by the pressure sensor 5; and obtains the target pressure as the first pressure value A through the mapping relationship. After comparing the latter two pressures, the control unit 4 obtains that the actual pressure is less than the first pressure value A, and the control unit 4 reduces the opening of the regulating valve 9 by a preset reduction value. After the opening of the regulating valve 9 is reduced, the above process is repeated. If the actual pressure is still less than the first pressure value A after continuing to perform the steps, the control unit 4 continues to reduce the opening of the regulating valve 9 according to the preset reduction value. When the piston 2 starts to compress the second elastic member 302, after the actual pressure is adjusted for many times in the first-stage stroke L1, the actual pressure is equal to or close to the first pressure value A. At this time, the above process is repeated, and the target pressure is changed to the second pressure value B, and the second pressure value B is less than the first pressure value A, that is, less than the actual pressure. The control unit 4 opens the opening of the regulating valve 9 to the maximum, and then repeats the pressure adjustment process. After the opening of the regulating valve 9 is opened to the maximum, the actual pressure is less than the second pressure value B, then the control unit 4 reduces the opening of the regulating valve 9 according to the preset reduction value, and then repeatedly executes the pressure regulation process until the actual pressure is equal to the second pressure value B. Under such a setting, increasing the opening of the regulating valve 9 is directly opened to the maximum, so the pressure regulation actually only needs to reduce the opening of the regulating valve 9 in one direction, and because the pressure regulation is continuously and rapidly repeated, the one-way regulation is conducive to being able to be performed multiple times in the same time, thereby improving the efficiency of the pressure regulation. When the piston 2 compresses the elastic part 13, the target pressure is 0, and the actual pressure must be greater than 0 at this time, so the opening of the regulating valve 9 is opened to the maximum, and the subsequent judgment can keep the actual pressure consistent with the target pressure.
[0080] Since the reduction value is a constant, and because the target pressure may not be completely consistent with the actual pressure under this constant value adjustment, a threshold range is set for the target pressure. When the actual pressure is within the threshold range of the target pressure, the actual pressure is consistent with or close to the target pressure.
[0081] The pedal simulator of the present invention uses external air as the air source, and adjusts the pedal feel by changing the opening of the regulating valve 9. Not only after the regulating valve 9 fails, the piston 2 can still compress the gas in the simulation cylinder 1 so that the pedal can be stepped on, thereby improving the safety of the pedal feel simulator. And compared with the combination of hydraulic pressure and motor and deceleration mechanism, the simulation cylinder 1 uses air, and the gas can be replenished by the atmosphere when the piston 2 is reset, and the structure is simpler. The control method of the pedal simulator of the present invention first considers the corresponding control strategy after the damage of different components, so that other intact components cooperate to replace the work of the damaged components and set the corresponding control strategy of the opening of the regulating valve 9, first, to make the use of the brake pedal safer, and second, to make the car execute according to the pedal feel mode selected by the driver as much as possible. In addition, in the custom mode of the present invention, the linear adjustment effect of the regulating valve 9 is combined with the established mapping relationship, and through the pressure adjustment process of the present invention, the control unit 4 can quickly change the gas in the simulation cylinder 1, so that the driver can more flexibly adjust the pedal feel he wants.
[0082] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent substitution or change made by a person skilled in the art based on the present invention is within the protection scope of the present invention.
Claims
1. A pedal feel simulator with adjustable pedal feel, comprising a simulation cylinder (1), a piston (2) and an elastic member (3) both installed in the simulation cylinder (1), wherein the elastic member (3) is located between the piston (2) and the bottom of the simulation cylinder (1), and the movement of the piston (2) toward the bottom of the simulation cylinder (1) compresses the elastic member (3). It is characterized in that The invention also comprises a control unit (4); a pressure sensor (5) electrically connected to the control unit (4) is installed in the simulation cylinder (1); the simulation cylinder (1) is connected to an intake pipeline (6) and an exhaust pipeline (7); a one-way valve (8) is arranged on the intake pipeline (6), and a regulating valve (9) electrically connected to the control unit (4) is arranged on the exhaust pipeline (7).
2. The pedal feel simulator with adjustable pedal feel according to claim 1, Features: At least two stroke sensors (10) for sensing the stroke of the piston (2) are installed in the simulation cylinder (1), and the stroke sensors (10) are electrically connected to the control unit (4).
3. The pedal feel simulator with adjustable pedal feel according to claim 2, Features: The elastic member (3) comprises two parts, namely a first elastic member (301) and a second elastic member (302); one end of the first elastic member (301) abuts against the bottom of the simulation cylinder (1), and the other end abuts against the piston (2); one end of the second elastic member (302) abuts against the bottom of the simulation cylinder (1), and the other end is a free end and is spaced apart from the piston (2).
4. The pedal feel simulator with adjustable pedal feel according to claim 3, Features: A limit base (11) is provided at the bottom of the simulation cylinder (1), and the simulation cylinder (1) is provided with a contact switch (12) for detecting contact between the piston (2) and the limit base (11), and the contact switch (12) is electrically connected to the control unit (4).
5. The pedal feel simulator with adjustable pedal feel according to claim 4, Features: The limiting base (11) is provided with an elastic portion (13) abutting against the piston (2).
6. The pedal feel simulator with adjustable pedal feel according to claim 4, Features: The first elastic member (301) is located between the limiting base (11) and the simulation cylinder (1); the limiting base (11) is provided with a first accommodating cavity (1101), and one end of the second elastic member (302) is located in the first accommodating cavity (1101).
7. The pedal feel simulator with adjustable pedal feel according to claim 5, Features: The piston (2) is provided with a second accommodating cavity (201); the free end of the second elastic member (302) is located in the second accommodating cavity (201) and has a distance from the inner bottom surface of the second accommodating cavity (201); and the piston (2) is provided with a limiting groove for accommodating the first elastic member (301).
8. The pedal feel simulator with adjustable pedal feel according to claim 2, Features: The outer surface of the piston (2) is provided with a sealing ring (202) that abuts against the inner wall of the simulation cylinder (1), and the end of the simulation cylinder (1) away from the bottom is provided with a limiting ring (14) that limits the piston (2) from leaving the simulation cylinder (1).
9. A control method for a pedal feel simulator with adjustable pedal feel according to any one of claims 2 to 8, Features: Setting a plurality of pedal feel modes and setting the opening of the regulating valve (9) corresponding to the different modes; When one of the pedal feel modes is selected, the control unit (4) collects data from the travel sensor (10) and the pressure sensor (5); When the pedal is stepped on, the states of the travel sensor (10), the pressure sensor (5) and the regulating valve (9) are detected and determined; if the travel sensor (10), the regulating valve (9) and the pressure sensor (5) are normal, the opening of the regulating valve (9) is controlled according to the selected pedal feel mode to provide the set pedal force; if all the travel sensors (10) are damaged, the regulating valve (9) is closed; if the pressure sensor (5) is abnormal, the regulating valve (9) is kept normally open; If the regulating valve (9) is damaged and the opening cannot be adjusted, the regulating valve (9) is kept normally open.
10. The control method of the pedal feel simulator according to claim 9, It is characterized in that The pedal feel modes include a comfort mode, a sports mode and a custom mode; in the comfort mode, the regulating valve (9) remains normally open; in the sports mode, the regulating valve (9) remains normally closed; in the custom mode, the pedal force is set and the actual pressure is obtained through the pressure sensor (5), and the control unit (4) controls the opening of the regulating valve (9) according to the target pressure so that the actual pressure is consistent with the target pressure.
11. The control method of the pedal feel simulator according to claim 10, It is characterized in that In the custom mode, a mapping relationship between the position of the piston (2) and the corresponding target pressure is established according to the set pedal force, the control unit (4) detects the stroke of the piston (2) through the stroke sensor (10) and obtains the target pressure according to the mapping relationship and obtains the actual pressure through the pressure sensor (5), and the control unit (4) controls the opening of the regulating valve (9) according to the difference between the target pressure and the actual pressure.
12. The control method of the pedal feel simulator according to claim 11, It is characterized in that In the custom mode, the specific process of pedal force adjustment is as follows: Step 1: the travel sensor (10) detects the position of the piston (2) and the pressure sensor (5) detects the actual pressure of the gas in the simulation cylinder (1); Step 2: The control unit (4) obtains a target pressure according to the position of the piston (2) and the mapping relationship, and compares the target pressure with the actual pressure; if the actual pressure is greater than the target pressure, step 3 is executed; if the actual pressure is less than the target pressure, step 4 is executed; if the target pressure is consistent with the actual pressure, step 5 is executed; Step 3: The control unit (4) increases the opening of the regulating valve (9) and then executes step 5; Step 4: The control unit (4) reduces the opening of the regulating valve (9) and then executes step 5; Step 5: Repeat steps 1 and 2.
13. The control method of the pedal feel simulator according to claim 12, It is characterized in that An increase value for increasing the opening of the regulating valve (9) and a decrease value for decreasing the opening of the regulating valve (9) are set; in step three, the control unit (4) increases the opening of the regulating valve (9) according to the increase value; in step four, the control unit (4) decreases the opening of the regulating valve (9) according to the decrease value.