JP3775236B2 - Stroke simulator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to a technical field of a stroke simulator that is applied to a brake system having a braking force generation device independent of a brake pedal, that is, a so-called brake-by-wire, and generates a reaction force according to the operation of the brake pedal.
[0002]
[Prior art]
Conventionally, as a stroke simulator, for example, one described in Japanese Patent Application Laid-Open No. 2000-280872 is known.
[0003]
In this publication, it is possible to provide a stroke simulator that can be applied to a brake device that does not use hydraulic pressure, can give a driver a good feeling of operation, and can reduce a space combined with related equipment. It is directly connected to the brake pedal and gives the brake pedal a reaction force against its operation, does not require hydraulic pressure, can control the reaction force characteristics finely, and further operates the brake pedal. A technique for applying a reaction force to a brake pedal by an electric actuator capable of electrically detecting the amount is described.
[0004]
[Problems to be solved by the invention]
However, since the conventional stroke simulator applies a reaction force to the brake pedal only by the electric actuator, there are problems as listed below.
(1) When operating the brake pedal, the maximum pressing force at the pedal end is 200 kgf and the maximum pressing speed at the pedal end is 400 mm / sec. An electric motor is required.
(2) When an operation to the brake pedal occurs, it is necessary to drive an electric motor with a large rated capacity, and in any case, the electric motor is driven to generate a reaction force. Become more.
(3) Since the pedal reaction force is generated only depending on the electric actuator, if a failure occurs in the control system of the electric actuator, the movement of the pedal and the pedal reaction force become unnatural, and the brake operation feeling is reduced. It will be damaged.
[0005]
The present invention has been made paying attention to the above-mentioned problems, and the object of the present invention is to reduce the size of the actuator and save power while having an adjustment function for obtaining a good brake pedal feeling. Another object of the present invention is to provide a stroke simulator that can ensure the minimum brake operability even if an actuator fails.
[0006]
[Means for Solving the Problems]
  In order to achieve the above object, in the invention described in claim 1,
  In a stroke simulator that is connected to a brake pedal and generates a reaction force according to the operation of the brake pedal,
  A piston member movable in response to movement of the brake pedal;
  A cylinder member that houses the piston member;
  A spring member housed in the cylinder member and having one end supported by a piston member;
  Supports the other end of the spring member and can slide in the direction of compression and tension of the spring memberAs the default position.A movable member arranged;
  In the direction of compressing the spring member or in the direction of pulling the spring memberThe movable memberMoveAnd an actuator having non-reversibility with respect to the reverse input from the movable member,
  Pedal position detecting means for detecting the pedal position of the brake pedal;
  Including the characteristic that the pedal reaction force decreases with increasing pedal position,To obtain the required stroke characteristics of pedal reaction forceFollowing the change in the pedal position detected by the pedal position detecting meansControl means for controlling the drive of the actuator;
  It is characterized by having.
[0008]
  Claim 2In the invention described inClaim 1In the stroke simulator described in
  The control means has a pedal position.In the case of the previous stroke areaThe actuator is not driven and the pedal position isIn the late stroke areaThe actuator is a means for driving the actuator in a direction to compress the spring member with respect to an increase in the pedal position.
[0009]
  Claim 3In the invention described inClaim 1In the stroke simulator described in
  The control means is means for driving the actuator in a direction in which the spring member is compressed after the actuator is once driven in the direction in which the spring member is pulled in response to an increase in pedal position.
[0011]
  Claim 4In the invention described inClaim 1In the stroke simulator described in
  Provided pedal speed detection means for detecting the pedal speed of the brake pedal,
  The control means includesDuring slow braking when the brake pedal is depressed slowlyThe actuator is a means for driving the actuator in the direction of compressing the spring member after the actuator is once driven in the direction of pulling the spring member in response to an increase in the pedal position.
[0012]
  Claim 5In the invention described inClaim 1In the stroke simulator described in
  Provided pedal speed detection means for detecting the pedal speed of the brake pedal,
  The control means includesDuring sudden braking when the brake pedal is depressed quicklyThe actuator is a means for driving the actuator in a direction to compress the spring member with respect to an increase in the pedal position.
[0013]
  Claim 6In the invention described inClaim 4 or claim 5In the stroke simulator described in
  The spring member is set so as to obtain a characteristic that maximizes the pedal reaction force,
  The control means is means for driving the actuator in a direction of pulling the spring member with respect to an increase in pedal position, and increasing the pulling amount of the spring member as the pedal speed is slow.
[0015]
  Claim 7In the invention described inClaim 1In the stroke simulator described in
  Vehicle speed detecting means for detecting the vehicle speed is provided;
  The control means includesWhen braking at low speedThe actuator is a means for driving the actuator in the direction of compressing the spring member after the actuator is once driven in the direction of pulling the spring member in response to an increase in the pedal position.
[0016]
  Claim 8In the invention described inClaim 1In the stroke simulator described in
  Vehicle speed detecting means for detecting the vehicle speed is provided;
  The control means includesWhen braking at high speedThe actuator is a means for driving the actuator in a direction to compress the spring member with respect to an increase in the pedal position.
[0017]
Operation and effect of the invention
In the first aspect of the present invention, when the brake pedal is depressed, the piston member in the cylinder member strokes according to the movement of the brake pedal, and the piston member is movable by the stroke of the piston member. The spring member interposed between the members is compressed. On the other hand, when the movable member is driven by the actuator, the spring member interposed between the piston member and the movable member is compressed or expanded. That is, the pedal reaction force is applied by the spring member according to the operation amount to the brake pedal and the control amount of the movable member.
[0018]
For example, when a spring member having a spring constant k is compressed by driving the movable member, when the driver's operation amount is X and the compression amount is Xa, the pedal reaction force F generated by the stroke simulator is F = k (X + Xa), and the pedal reaction force is greater than when the movable member is fixed. On the contrary, when the spring member having the spring constant k is pulled by driving the movable member, when the driver's operation amount is X and the pull amount is Xb, the pedal reaction force F generated by the stroke simulator is F = k (X-Xb), and the pedal reaction force becomes smaller than when the movable member is fixed. As described above, the brake pedal feeling can be arbitrarily adjusted by controlling and driving the position of the movable member.
[0019]
Further, in the case of the conventional stroke simulator in which the brake pedal is directly driven by the electric actuator, the pedal reaction force is handled only by the motor, so that a very large motor is required. Since the force is handled by the spring member and the actuator, the output of the motor used as a component of the actuator is greatly reduced compared to the conventional one, and the movable member can be sufficiently driven by a small motor.
[0020]
  In addition, in the control means:Including the characteristic that the pedal reaction force decreases with increasing pedal position,To obtain the required stroke characteristics of pedal reaction forceFollowing the change in the pedal position detected by the pedal position detecting meansThe drive of the actuator is controlled. For example, as in the invention according to claim 2, when the pedal position is in the first stroke region, the actuator is not driven, and when the pedal position is in the second stroke region, the direction in which the spring member is compressed as the pedal position increases. Or the actuator is driven in the direction in which the spring member is once pulled and then the spring member is compressed in the direction in which the spring member is compressed. Driven.
[0021]
  in this way,Including the characteristic that the pedal reaction force decreases with increasing pedal position,To obtain the required stroke characteristics of pedal reaction forceFollowing the change in the pedal position detected by the pedal position detecting meansSince the drive of the actuator is controlled, not only the magnitude of the reaction force of the brake pedal but also the stroke characteristic of the pedal reaction force can be finely adjusted.
[0022]
  Claims 4 and 5In the above-described invention, in the control means, the driving of the actuator is controlled in accordance with the change in the pedal position detected by the pedal position detecting means and the pedal speed detected by the pedal speed detecting means. For example,Claim 4Like the invention described inDuring slow braking when the brake pedal is depressed slowlyIn response to an increase in the pedal position, the actuator is once driven in the direction of pulling the spring member, and then the actuator is driven in the direction of compressing the spring member.Claim 5Like the invention described inDuring sudden braking when the brake pedal is depressed quicklyAs the pedal position increases, the actuator is driven in a direction to compress the spring member.
[0023]
In this way, the actuator drive is controlled according to changes in the detected pedal position and pedal speed, so when the brake pedal is depressed slowly, the reaction force is reduced and the brake pedal feels soft. On the other hand, when the brake pedal is depressed quickly, the reaction force is increased, and the stroke characteristic of the pedal reaction force is finely adjusted according to the pedal speed, such as giving a firm feeling as a brake pedal feeling. be able to.
[0024]
  Claim 6In the invention described in (2), the spring member is set in advance so as to obtain a characteristic that maximizes the pedal reaction force, and in the control means, the actuator is driven in the direction of pulling the spring member with respect to an increase in the pedal position. At the same time, the slower the pedal speed, the greater the amount by which the spring member is pulled.
[0025]
That is, when the pedal speed is high, the pedal reaction force is generated only by the spring member, and when the pedal speed is in the normal range, the pedal reaction force is generated by controlling only the pulling direction for reducing the reaction force by the spring member. It will be.
[0026]
Therefore, it is not necessary for the actuator to output the maximum torque at the maximum speed, and it is only necessary to output the maximum torque in the normal range of the pedal speed.
[0027]
  Claims 7 and 8In the above-described invention, the driving of the actuator is controlled in the control means in accordance with a change in the pedal position detected by the pedal position detecting means and the vehicle speed detected by the vehicle speed detecting means. For example,Claim 7Like the invention described inWhen braking at low speedIn response to an increase in the pedal position, the actuator is once driven in the direction of pulling the spring member, and then the actuator is driven in the direction of compressing the spring member.Claim 8Like the invention described inWhen braking at high speedAs the pedal position increases, the actuator is driven in a direction to compress the spring member.
[0028]
As described above, since the actuator drive is controlled according to the detected pedal position and vehicle speed change, the reaction force is reduced and the brake pedal feels soft when braking at low speed. On the other hand, the stroke characteristics of the pedal reaction force can be finely adjusted according to the vehicle speed, such as increasing the reaction force and giving a firm feeling as a pedal feeling when braking in a high-speed running state. .
[0029]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, an embodiment for realizing a stroke simulator according to the present invention will be described in claim 1.And claim 2A first embodiment corresponding toClaim 3A second embodiment corresponding toClaims 4 and 5A third embodiment corresponding toClaim 6A fourth embodiment corresponding toClaims 7 and 8This will be described based on the fifth embodiment corresponding to the above.
[0030]
(First embodiment)
First, the configuration will be described.
FIG. 1 is an overall view showing a brake operation unit 2 to which the stroke simulator 1 of the first embodiment is applied. In FIG. 1, 3 is a brake pedal, 4 is a rotating shaft, 5 is a vehicle body, 6 is a support member, 7 Is a rotating shaft, 8 is a clevis, 12 is an electric motor, 14 is a speed reducer, 26 is a stroke sensor (pedal position detecting means), 27 is a vehicle speed sensor (vehicle speed detecting means), and 28 is a controller (control means). .
[0031]
The brake operation unit 2 includes a brake pedal 3 that is depressed by a driver, a rotating shaft 4 that is fixed to the brake pedal 3, a support member 6 that rotatably supports the rotating shaft 4 on a vehicle body 5, and the brake In order to connect the pedal 3 and the stroke simulator 1, a rotating shaft 7 provided on the brake pedal 3, a clevis 8 that converts a locus of the rotating shaft 7 when the pedal is operated into a linear motion, and a connection to the clevis 8 The stroke simulator 1 generates a reaction force against the pedal operation. The stroke simulator 1 receives the reaction force of the brake operation unit 2 by being fixed to the vehicle body 5. An electric motor 12 and a speed reducer 14 are provided on the vehicle body 5 side of the stroke simulator 1.
[0032]
A stroke sensor 26 is attached to the brake pedal 3 to detect the pedal position, and a vehicle speed sensor 27 is attached to the vehicle to detect the vehicle speed. A controller 28 that receives these sensor signals and controls and drives the electric motor 12 of the actuator is electrically disposed between the sensors 26 and 27 and the electric motor 12.
[0033]
The controller 28 is composed of an arithmetic processing unit such as a microcomputer, and calculates the pedal speed based on the signal of the stroke sensor 26, or drives and controls the electric motor 12 based on various signals and internally calculated signals. The pedal reaction force is generated. Such basic control arithmetic processing is performed in accordance with a predetermined logic in the controller 28. As the control mode, conventionally known feedback control, open control, or the like can be used.
[0034]
FIG. 2 is a sectional view showing the stroke simulator 1 of the first embodiment. In FIG. 2, 9 is a cylinder member, 10 is a pedal side opening, 11 is a piston, 12 is an electric motor, 13 is a motor shaft, and 14 is Reduction gear, 15 is a primary gear, 16 is a secondary gear, 17 is a rotating shaft, 18 is a motor side opening, 19 is a male screw, 20 is a ball, 21 is a movable member, 22 is a notch, 23 is a protrusion, Reference numeral 24 denotes a spring member, 25 denotes a skirt portion, and 29 denotes a linear conversion mechanism.
[0035]
The cylinder member 9 is a cylindrical member with both ends closed. A pedal side opening 10 through which the shaft portion of the piston member 11 is inserted is formed on the front side, and a rotary shaft 17 of the actuator is inserted on the back side. The motor side opening 18 is formed, and the piston member 11, the movable member 21, and the spring member 24 are accommodated therein.
[0036]
The piston member 11 is a member that is connected to the clevis 8 and is slidable in conjunction with the movement of the brake pedal 3. The shaft portion 11 a on the side connected to the clevis 8 is an opening on the pedal side of the cylinder member 9. The piston portion 11 b that protrudes from 10 and is accommodated in the cylinder member 9 is biased by a spring member 24.
[0037]
The spring member 24 is housed in the cylinder member 9, one spring end portion is supported by the piston portion 11 b of the piston member 11, and the other spring end portion is supported by the skirt portion 25 of the movable member 21. .
[0038]
The movable member 21 supports the other spring end of the spring member 24 and is arranged to be slidable in the compression and tension directions of the spring member 24 via the linear conversion mechanism 29 with respect to the rotating shaft 17. .
[0039]
The movable member 21 is moved in the movable direction by the electric motor 12, the speed reducer 14, and the linear conversion mechanism 29, and the rotational force from the electric motor 12 is transmitted, but against the reverse input from the movable member 21 by the spring member 24. Thus, an actuator having a non-invertibility with low transmission efficiency is configured.
[0040]
The speed reducer 14 includes a primary gear 15 provided on the motor shaft 13 of the electric motor 12 and a secondary gear 16 that meshes with the primary gear 15 and is provided on the rotary shaft 17. The rotating shaft 17 of the secondary gear 16 protrudes into the cylinder member 9 through the motor side opening 18 of the cylinder member 9.
[0041]
The linear conversion mechanism 29 includes a ball screw that screws the rotating shaft 17 and the movable member 21 and a stopper structure that restricts the rotation of the movable member 21. The ball screw includes a male screw 19 formed at the tip of the rotary shaft 17, a female screw formed on the movable member 21 disposed on the outer periphery of the male screw 19, and a space between the male screw 19 and the female screw. And a mounted ball 20. The stopper structure includes a notch portion 22 formed in the skirt portion 25 of the movable member 21 and a protrusion 23 that is fixed to the cylinder member 9 and fits into the notch portion 22.
[0042]
The example shown in FIG. 3 is an example in which the electric motor 12 is arranged on the pedal side with respect to the speed reducer 14, and the axial direction is shortened. In the example shown in FIG. This is an example in which the speed reducer 14 is arranged in a direction perpendicular to the direction and the form of the speed reducer 14 is changed to improve the attachment of the electric motor 12 to the vehicle body 5, and the stroke simulator 1 is exactly the same as the example shown in FIG. That is, the examples shown in FIGS. 2 to 4 differ only in the type of the speed reducer 14 and the arrangement of the electric motor 12, and any of them may be selected depending on the applicable vehicle type and the like.
[0043]
Next, the operation will be described.
[0044]
[Pedal reaction force characteristic control processing]
FIG. 5 is a flowchart showing the flow of the pedal reaction force characteristic control process of the first embodiment executed by the controller 28. Each step will be described below.
[0045]
In step 50, the pedal operation amount P is read by the stroke sensor 26. In the next step 51, it is determined whether or not the pedal operation amount P exceeds the first set value P1 (threshold value for determining whether or not braking). If YES, the process proceeds to step 52. If NO, Return to step 50. In the next step 52, it is determined whether or not the pedal operation amount P exceeds the second set value P2 (threshold value for determining whether the motor is driven). If YES, the process proceeds to step 53. If NO, Return to step 50. In the next step 53, the motor command value X^*(Actuator position for moving the movable member 21 in the compression direction) is X^*= X1 (P) is calculated by a linear function formula. In the next step 54, the motor command value X^*Is output to the electric motor 12.
[0046]
[Pedal reaction force characteristic control action]
When a depression operation is performed on the brake pedal 3, first, in a region where the pedal operation amount P is equal to or smaller than the second set value P2, the process of step 50 → step 51 → step 52 is repeated in the flowchart of FIG. The motor 12 remains non-driven, and the movable member 21 remains fixed at the initial setting position. Therefore, the piston member 11 in the cylinder member 9 strokes according to the movement of the brake pedal 3, and the spring member 24 interposed between the piston member 11 and the movable member 21 is caused by the stroke of the piston member 11. The pedal reaction force is applied by the spring member 24 in accordance with the pedal operation amount P.
[0047]
And in the area | region where the pedal operation amount P exceeds 2nd setting value P2, the process of step 50-> step 51-> step 52-> step 53-> step 54 is repeated in the flowchart of FIG. Driven according to the magnitude of P, the movable member 21 is slid in the direction of compressing the spring member 24 from the initial setting position. Therefore, a pedal reaction force is applied by the spring member 24 in accordance with the pedal operation amount P and the control amount of the movable member 21 in the compression direction.
[0048]
That is, the motor command value X^*Actuator position X^*When the pedal operation amount P is paraphrased as the pedal position P, as shown in FIG. 6 (a), until the pedal position P reaches P1, the actuator position X^*If the spring member 24 is left in the initial position where neither compression nor tension is applied and the pedal position P exceeds P1, the actuator position X^*Is moved in proportion to the pedal position P to the spring compression side.
[0049]
Therefore, as shown in FIG. 6B, until the pedal position P reaches P1, the pedal reaction force characteristic by the single spring is obtained. When the pedal position P exceeds P1, the pedal reaction force by the single spring is compressed by the actuator. It becomes the pedal reaction force characteristic that the pedal reaction force of the minute is added.
That is, when the spring member 24 having the spring constant k is compressed by driving the movable member 21, the pedal reaction force F generated by the stroke simulator 1 is given by the compression amount Xa when the pedal operation amount of the driver is P. F = k (P + Xa), and the pedal reaction force becomes larger than that in the non-control time in which the movable member 21 remains fixed.
[0050]
Next, the effect will be described.
[0051]
(1) The stroke simulator 1 that is connected to the brake pedal 3 and generates a reaction force in response to the operation of the brake pedal 3 is a piston member 11, a cylinder member 9, a spring member 24, a movable member 21, Since the electric motor 12, the speed reducer 14, the linear conversion mechanism 29, and the controller 28 that controls the driving of the electric motor 12 according to the sensor signal from the stroke sensor 26 are provided, a good brake pedal feeling is achieved. While having the adjustment function to be obtained, the electric motor 12 can be reduced in size and power can be saved, and even when the actuator system fails, the minimum brake operability can be ensured.
[0052]
That is, the position of the movable member 21 is controlled and driven such that when the spring member 24 is compressed by driving the movable member 21, the pedal reaction force increases, and conversely, when the spring member 24 is pulled, the pedal reaction force decreases. Thus, the brake pedal feeling can be arbitrarily adjusted.
[0053]
Further, in the case of the conventional stroke simulator in which the brake pedal is directly driven by the electric actuator, the pedal reaction force is handled only by the motor, so that a very large motor is required, whereas the pedal reaction force is generated by the spring member 24 and the movable member. Since the actuator 21 moves the actuator 21, the output of the electric motor 12 used as a component of the actuator is greatly reduced as compared with the prior art, and the movable member 21 can be sufficiently driven by the small electric motor 12.
[0054]
In addition, since the small electric motor 12 is driven, even when the brake operation is always performed, power can be saved. In addition, as in the first embodiment, the movable member 21 is kept fixed in the first stroke region of the brake pedal 3, and the movable member 21 is driven and controlled by the actuator only in the second stroke region of the brake pedal 3. Thus, when a brake operation is performed, it is possible to save power compared to a conventional stroke simulator that always needs to drive the electric actuator.
[0055]
Further, even if it is assumed that the movable member 21 is fixed due to the failure of the actuator, the pedal effort from the brake pedal 3 is received by the movable member 21 via the spring member 24 due to the irreversibility of the actuator. That is, at least the pedal reaction force characteristic of the spring member 24 can be ensured in the brake operation after the actuator failure.
[0056]
(2) Since the drive of the electric motor 12 is controlled according to the change in the pedal operation amount P detected by the stroke sensor 26, not only the magnitude of the reaction force of the brake pedal 3, but also the stroke characteristics of the pedal reaction force Can be finely adjusted according to the required performance.
[0057]
(3) When the pedal operation amount P is equal to or less than the second set value P2, the spring member is increased with respect to the increase in the pedal operation amount P when the pedal operation amount P exceeds the second set value P2 without driving the electric motor 12. Since the electric motor 12 is driven in the direction of compressing 24, as shown in FIG. 6 (b), the increase rate of the pedal reaction force is small with respect to the depression operation amount in the first stroke region of the brake pedal 3, and the brake In the latter stroke region of the pedal 3, it is possible to obtain a pedal reaction force characteristic in which the increase rate of the pedal reaction force with respect to the depression operation amount is large.
[0058]
(Second embodiment)
2nd Example is an example which performs drive control of the electric motor 12 which makes a pedal feeling softer further than 1st Example in the first stroke area of the brake pedal 3 with little depression amount.
[0059]
Since the configuration of the second embodiment is the same as that of the first embodiment (FIGS. 1 to 4), illustration and description thereof are omitted.
[0060]
Next, the operation will be described.
[0061]
[Pedal reaction force characteristic control processing]
FIG. 7 is a flowchart showing the flow of the pedal reaction force characteristic control process of the second embodiment executed by the controller 28. Each step will be described below.
[0062]
In step 70, the pedal operation amount P is read by the stroke sensor 26. In the next step 71, it is determined whether or not the pedal operation amount P exceeds the first set value P1 (threshold value for determining whether or not braking). If YES, the process proceeds to step 72. If NO, Return to step 70. In the next step 72, the motor command value X^*(Actuator position for moving the movable member 21 in the compressing or pulling direction) is X^*= Calculated by an equation based on a quadratic function of X2 (P). In the next step 73, the motor command value X^*Is output to the electric motor 12.
[0063]
[Pedal reaction force characteristic control action]
When the stepping operation is performed on the brake pedal 3, the processing of Step 70 → Step 71 → Step 72 → Step 73 is repeated in the flowchart of FIG. 7, and the electric motor 12 is driven according to the magnitude of the pedal operation amount P. Is done.
[0064]
That is, the motor command value X^*Actuator position X^*When the pedal operation amount P is paraphrased as the pedal position P, as shown in FIG. 8 (a), until the pedal position P reaches P3, the actuator position X^*When the pedal position P exceeds P3, the actuator position X^*Is controlled so as to move in a quadratic function relationship with the pedal position P, such that is the spring compression side.
[0065]
Therefore, as shown in FIG. 8 (b), until the pedal position P reaches P3, the pedal reaction force obtained by subtracting the pedal reaction force of the actuator from the pedal reaction force by a single spring is obtained, and the pedal position P exceeds P3. Then, the pedal reaction force characteristic is obtained by adding the pedal reaction force of the compression by the actuator to the pedal reaction force of the spring alone.
That is, when the spring member 24 having the spring constant k is pulled by driving the movable member 21, when the driver's pedal operation amount is P, and the pull amount is Xb, the pedal reaction force F generated by the stroke simulator 1 is F = k (P−Xb), and the pedal reaction force becomes smaller than that in the non-control time in which the movable member 21 is kept in a fixed state.
[0066]
Next, the effect will be described.
[0067]
In the stroke simulator 1 of the second embodiment, the following effects can be obtained in addition to the effects (1) and (2) of the first embodiment.
[0068]
(4) Since the electric motor 12 is once driven in the direction in which the spring member 24 is pulled in response to the increase in the pedal operation amount P, the electric motor 12 is driven in the direction in which the spring member 24 is compressed. ), The pedal reaction force is kept small with respect to the depression operation amount in the first stroke region of the brake pedal 3, and the rate of increase in the pedal reaction force gradually increases with respect to the depression operation amount in the second stroke region of the brake pedal 3. Increased pedal reaction force characteristics can be obtained.
[0069]
(Third embodiment)
The third embodiment is an example in which drive control of the electric motor 12 is performed in accordance with changes in the pedal operation amount P and the pedal speed ΔP.
[0070]
Since the configuration of the third embodiment is the same as that of the first embodiment (FIGS. 1 to 4), illustration and description thereof are omitted.
[0071]
Next, the operation will be described.
[0072]
[Pedal reaction force characteristic control processing]
FIG. 9A is a flowchart showing the flow of the pedal reaction force characteristic control process of the third embodiment executed by the controller 28, and each step will be described below.
[0073]
In step 90, the pedal operation amount P is read by the stroke sensor 26. In the next step 91, the pedal speed ΔP is calculated by calculation (differential calculation) of the time change amount of the read pedal operation amount P. In the next step 92, the actuator position map shown in FIG. 10 is read. In the next step 93, the motor command value X^*(Actuator position for moving the movable member 21 in the compressing or pulling direction) is X^*= X3 (P, ΔP) is calculated by an expression representing an actuator position map. In the next step 94, the motor command value X^*Is output to the electric motor 12.
[0074]
[Pedal reaction force characteristic control action]
When the depression operation is performed on the brake pedal 3, the process of step 90 → step 91 → step 92 → step 93 → step 94 is repeated in the flowchart of FIG. It is driven according to the magnitude of the pedal speed ΔP.
[0075]
That is, the motor command value X^*Actuator position X^*In other words, as shown in FIG. 10, in the region where the pedal operation amount P is small and the pedal speed ΔP is slow, the actuator position X^*When the pedal operation amount P is larger than that, the higher the pedal speed ΔP, the higher the actuator position X^*The actuator position X with the pedal operation amount P and the pedal speed ΔP as parameters.^*Control to determine is performed.
[0076]
Therefore, as shown in FIG. 9 (b), when the pedal speed is slow, that is, at the time of so-called gentle braking, for example, until the pedal operation amount P reaches P4, the pedal reaction force by a single spring is applied to the pedal of the tension by the actuator. When the pedal operation amount P exceeds P4, the pedal reaction force characteristic is obtained by adding the pedal reaction force corresponding to the compression by the actuator to the pedal reaction force by a single spring. When the pedal speed is high, that is, during so-called sudden braking, the pedal reaction force characteristic is obtained by adding the pedal reaction force of the compression by the actuator to the pedal reaction force of the single spring regardless of the pedal operation amount P.
[0077]
Next, the effect will be described.
[0078]
In the stroke simulator 1 of the third embodiment, the following effects can be obtained in addition to the effects (1) and (2) of the first embodiment.
[0079]
(5) Since the drive of the electric motor 12 is controlled according to the change in the pedal operation amount P detected by the stroke sensor 26 and the calculated pedal speed ΔP, the pedal reaction is changed according to the change in the pedal speed ΔP. The stroke characteristics of force can be finely adjusted.
[0080]
(6) When the pedal speed ΔP is slow, the electric motor 12 is once driven in the direction in which the spring member 24 is pulled in response to the increase in the pedal operation amount P, and then the electric motor 12 is driven in the direction in which the spring member 24 is compressed. Therefore, as shown in FIG. 9 (b), the pedal reaction force can be suppressed to a small level and a soft feeling can be provided as a brake pedal feeling during slow braking in which the brake pedal 3 is slowly depressed.
[0081]
(7) When the pedal speed ΔP is high, the electric motor 12 is driven in the direction in which the spring member 24 is compressed with respect to the increase in the pedal operation amount P. Therefore, as shown in FIG. At the time of sudden braking when 3 is stepped on quickly, the pedal reaction force becomes large, and it is possible to give a firm feeling as a brake pedal feeling.
[0082]
(Fourth embodiment)
In the fourth embodiment, the spring member 24 is set in advance so as to obtain a characteristic that maximizes the pedal reaction force. In the controller 28, the spring member 24 is pulled in the direction in which the pedal operation amount P increases. In this example, drive control of the electric motor 12 is performed, and the drive control of the electric motor 12 is performed such that the amount by which the spring member 24 is pulled is increased as the pedal speed ΔP is slower.
[0083]
Since the configuration of the fourth embodiment is the same as that of the first embodiment (FIGS. 1 to 4), illustration and description thereof are omitted.
[0084]
Next, the operation will be described.
[0085]
[Pedal reaction force characteristic control processing]
FIG. 11A is a flowchart showing the flow of the pedal reaction force characteristic control process of the fourth embodiment executed by the controller 28. Each step will be described below.
[0086]
In step 110, the pedal operation amount P is read by the stroke sensor 26. In the next step 111, the pedal speed ΔP is calculated by calculation (differential calculation) of the time change amount of the read pedal operation amount P. In the next step 112, the actuator position map shown in FIG. 12 is read. In the next step 113, the motor command value X^*(Actuator position for moving the movable member 21 in the pulling direction) is X^*= X5 (P, ΔP) is calculated by an expression representing an actuator position map. In the next step 114, the motor command value X^*Is output to the electric motor 12.
[0087]
[Pedal reaction force characteristic control action]
When the depression operation is performed on the brake pedal 3, the process of step 110 → step 111 → step 112 → step 113 → step 114 is repeated in the flowchart of FIG. It is driven according to the magnitude of the pedal speed ΔP.
[0088]
That is, the motor command value X^*Actuator position X^*In other words, as shown in FIG. 12, the actuator position X increases as the pedal operation amount P increases.^*Is set to the spring tension side, and the pedal operation amount P and the pedal speed ΔP are used as parameters to increase the actuator position X so that the slower the pedal speed ΔP, the more the pulling amount of the spring member 24 increases.^*Control to determine is performed.
[0089]
Therefore, as shown in FIG. 11 (b), when the pedal speed is slow, that is, at the time of so-called slow braking, the higher the pedal reaction amount by the spring alone, the larger the pedal operation amount P, the larger the pulling amount by the actuator (compared to the sudden braking). Pedal reaction force characteristics with reduced pedal reaction force due to large pulling amount). When the pedal speed is high, so-called sudden braking, the pedal reaction force due to a large pulling amount by the actuator (a smaller pulling amount compared with the gentle braking) is increased as the pedal operation amount P increases from a high pedal reaction force due to a single spring. Reduced pedal reaction force characteristics.
[0090]
Next, the effect will be described.
[0091]
In the stroke simulator 1 of the fourth embodiment, the following effects can be obtained in addition to the effects (1) and (2) of the first embodiment.
[0092]
(8) The spring member 24 is set in advance so as to obtain a characteristic that maximizes the pedal reaction force. In the controller 28, the electric motor 12 is pulled in the direction in which the spring member 24 is pulled with respect to an increase in the pedal operation amount P. As the pedal speed ΔP is slower, the drive control of the electric motor 12 that increases the pulling amount of the spring member 24 is performed, so that the electric motor 12 used as an actuator can be greatly reduced in size. Can do.
[0093]
That is, when the pedal speed ΔP is high, the pedal reaction force is generated only by the spring member 24, and when the pedal speed ΔP is in the normal range, the control is performed only in the pulling direction for reducing the reaction force by the spring member 24. This is because the pedal reaction force is generated, and the electric motor 12 used as the actuator does not need to output the maximum torque at the maximum speed, and it is only necessary to output the maximum torque in the normal range of the pedal speed ΔP.
[0094]
Incidentally, in the conventional case where the brake pedal is directly driven by an electric actuator, the necessary motor specifications are as follows.
For example, in a brake pedal with a maximum pedaling force = 200kgf and a pedal maximum speed = 400mm / sec, if a linear actuator is installed at a lever ratio of 1/4, the maximum thrust of the linear actuator = 200 x 4 = 800kgf, maximum speed = 400/4 = 100mm / sec. If the direct acting actuator has a lead of 4.0 mm, the maximum torque of the motor is 800 kgf × 4 mm / 3.14 = 1.02 kgfm, and the maximum rotation speed = 100 mm / sec × 3.14 / 4 mm × 60 sec / min = 4710 rpm. Therefore, the motor output requires a very large motor of 1.02 kgf × 4710 rpm × 1.02374 = 4.8 kW.
On the other hand, according to the stroke simulator 1 of the fourth embodiment, when the maximum pedaling force is 200 kgf and the pedal speed in the pedal normal range is about 40 mm / sec, the rotation speed of the motor is 471 rpm and the motor output is 0.4 by the same calculation. Reduced to kW.
[0095]
(5th Example)
The fifth embodiment is an example in which drive control of the electric motor 12 is performed in accordance with changes in the pedal operation amount P and the vehicle speed V.
[0096]
Since the configuration of the fifth embodiment is the same as that of the first embodiment (FIGS. 1 to 4), illustration and description thereof are omitted.
[0097]
Next, the operation will be described.
[0098]
[Pedal reaction force characteristic control processing]
FIG. 13A is a flowchart showing the flow of the pedal reaction force characteristic control process of the fifth embodiment executed by the controller 28, and each step will be described below.
[0099]
In step 130, the pedal operation amount P is read by the stroke sensor 26. In the next step 131, the vehicle speed V is read by the vehicle speed sensor 27. In the next step 132, the actuator position map shown in FIG. 14 is read. In the next step 133, the motor command value X^*(Actuator position for moving the movable member 21 in the compressing or pulling direction) is X^*= Calculated by an expression representing an actuator position map of X4 (P, V). In the next step 134, the motor command value X^*Is output to the electric motor 12.
[0100]
[Pedal reaction force characteristic control action]
When the depression operation is performed on the brake pedal 3, the process of step 130 → step 131 → step 132 → step 133 → step 134 is repeated in the flowchart of FIG. It is driven according to the magnitude of the vehicle speed V.
[0101]
That is, the motor command value X^*Actuator position X^*In other words, as shown in FIG. 14, in the region where the pedal operation amount P is small and the vehicle speed V is low, the actuator position X^*Is the spring tension side, and when the pedal operation amount P is larger than that, the higher the vehicle speed V, the more the actuator position X^*The actuator position X with the pedal operation amount P and the vehicle speed V as parameters.^*Control to determine is performed.
[0102]
Therefore, as shown in FIG. 13B, when the vehicle speed V is slow, that is, when braking in a so-called low speed running state, for example, until the pedal operation amount P reaches P5, the pedal reaction force by a single spring is affected by the actuator. When the pedal operation amount P exceeds P5, the pedal reaction force is obtained by adding the pedal reaction force of the compression by the actuator to the pedal reaction force of the spring alone. When the vehicle speed V is high, that is, at the time of braking in a so-called high speed running state, the pedal reaction force characteristic is obtained by adding the pedal reaction force of the compression by the actuator to the pedal reaction force of the single spring regardless of the pedal operation amount P.
[0103]
Next, the effect will be described.
[0104]
In the stroke simulator 1 of the fifth embodiment, the following effects can be obtained in addition to the effects (1) and (2) of the first embodiment.
[0105]
(9) Since the drive of the electric motor 12 is controlled in accordance with the change in the pedal operation amount P detected by the stroke sensor 26 and the vehicle speed V detected by the vehicle speed sensor 27, the pedal is controlled in accordance with the change in the vehicle speed V. The stroke characteristics of the reaction force can be finely adjusted.
[0106]
(10) When the vehicle speed V is low, the electric motor 12 is once driven in the direction in which the spring member 24 is pulled in response to the increase in the pedal operation amount P, and then the electric motor 12 is driven in the direction in which the spring member 24 is compressed. Therefore, as shown in FIG. 13 (b), the pedal reaction force can be kept small during braking in a low-speed traveling state such as an urban area, and a soft feeling can be obtained as a brake pedal feeling.
[0107]
(11) When the vehicle speed V is high, the electric motor 12 is driven in the direction in which the spring member 24 is compressed with respect to the increase in the pedal operation amount P. Therefore, as shown in FIG. When braking in a high-speed running state, the pedal reaction force becomes large, and it is possible to give a firm feeling as a brake pedal feeling.
[0108]
(Other examples)
As mentioned above, although the stroke simulator of this invention has been demonstrated based on 1st Example-5th Example, about a concrete structure, it is not restricted to these Examples, Each claim of a claim Design changes and additions are permitted without departing from the spirit of the invention.
[0109]
For example, in the first to fifth embodiments, an example in which the actuator is configured by the electric motor 12, the speed reducer 14, and the linear conversion mechanism 29 is shown as the actuator, but the movable member is moved in the movable direction, The actuator is not limited to the one shown in the embodiment as long as the actuator has non-reciprocity with respect to the reverse input.
[0110]
In the first to fifth embodiments, the example in which the driving of the actuator is controlled according to the pedal operation amount, (pedal operation amount + pedal speed), and (pedal operation amount + vehicle speed) is shown. Detection means other than pedal operation amount detection means, pedal speed detection means, vehicle speed detection means, for example, vehicle deceleration detection means, etc. may be used, and for example, (pedal operation amount + pedal speed + vehicle speed), etc. You may make it control the drive of an actuator according to one or more vehicle state information.
[Brief description of the drawings]
FIG. 1 is an overall system diagram showing a brake operation unit to which a stroke simulator of a first embodiment is applied.
FIG. 2 is a sectional view showing a stroke simulator of the first embodiment.
FIG. 3 is a cross-sectional view showing another embodiment of the stroke simulator of the first embodiment.
FIG. 4 is a cross-sectional view showing another embodiment of the stroke simulator of the first embodiment.
FIG. 5 is a flowchart showing the flow of a pedal reaction force control process performed by the controller of the first embodiment.
FIG. 6 is an actuator position characteristic diagram and a pedal reaction force characteristic diagram in the stroke simulator of the first embodiment.
FIG. 7 is a flowchart showing the flow of a pedal reaction force control process performed by the controller of the second embodiment.
FIG. 8 is an actuator position characteristic diagram and a pedal reaction force characteristic diagram in the stroke simulator of the second embodiment.
FIG. 9 is a flowchart showing the flow of a pedal reaction force control process performed by the controller of the third embodiment and a pedal reaction force characteristic diagram in the stroke simulator of the third embodiment.
FIG. 10 is an actuator position characteristic diagram in the stroke simulator of the third embodiment.
FIG. 11 is a flowchart showing the flow of a pedal reaction force control process performed by the controller of the fourth embodiment and a pedal reaction force characteristic diagram in the stroke simulator of the third embodiment.
FIG. 12 is an actuator position characteristic diagram in the stroke simulator of the fourth embodiment.
FIG. 13 is a flowchart showing the flow of a pedal reaction force control process performed by the controller of the fifth embodiment and a pedal reaction force characteristic diagram in the stroke simulator of the third embodiment.
FIG. 14 is an actuator position characteristic diagram in the stroke simulator of the fifth embodiment.
[Explanation of symbols]
1 Stroke simulator
2 Brake operation section
3 Brake pedal
4 Rotating shaft
5 Body
6 Support members
7 Rotating shaft
8 Clevis
9 Cylinder member
10 Pedal side opening
11 Piston
12 Electric motor
13 Motor shaft
14 Reducer
15 Primary gear
16 Secondary gear
17 Rotating shaft
18 Motor side opening
19 Male thread
20 balls
21 Movable members
22 Notch
23 Protrusions
24 Spring member
25 Skirt
26 Stroke sensor (pedal position detection means)
27 Vehicle speed sensor (vehicle speed detection means)
28 controller (control means)
29 Linear conversion mechanism

Claims (8)

In a stroke simulator that is connected to a brake pedal and generates a reaction force according to the operation of the brake pedal,
A piston member movable in response to movement of the brake pedal;
A cylinder member that houses the piston member;
A spring member housed in the cylinder member and having one end supported by a piston member;
A movable member that supports the other end of the spring member and is arranged with a position where the spring member can slide in the compression and tension directions as an initial setting position ;
Said movable member in a direction to pull the direction or the spring member to compress the spring member causes the move, an actuator having a non-inverting with respect to reverse input from the movable member,
Pedal position detecting means for detecting the pedal position of the brake pedal;
The actuator is driven following the change in the pedal position detected by the pedal position detecting means so as to obtain the required stroke characteristic of the pedal reaction force, including the characteristic that the pedal reaction force decreases with respect to the increase in the pedal position. Control means for controlling;
A stroke simulator characterized by comprising: The stroke simulator according to claim 1,
The control means does not drive the actuator when the pedal position is in the first stroke area, and drives the actuator in a direction to compress the spring member with respect to an increase in the pedal position when the pedal position is in the second stroke area. The stroke simulator characterized by being. The stroke simulator according to claim 1,
The control means is means for driving the actuator in a direction in which the spring member is compressed after the actuator is once driven in the direction in which the spring member is pulled in response to an increase in pedal position. The stroke simulator according to claim 1,
Provided pedal speed detection means for detecting the pedal speed of the brake pedal,
The control means is means for driving the actuator in a direction in which the spring member is compressed after the actuator is once driven in the direction of pulling the spring member in response to an increase in the pedal position when the brake pedal is slowly depressed. A stroke simulator characterized by being. The stroke simulator according to claim 1,
Provided pedal speed detection means for detecting the pedal speed of the brake pedal,
The control means is a means for driving the actuator in a direction to compress the spring member in response to an increase in the pedal position when the pedal speed is high during sudden braking in which the brake pedal is depressed quickly. . In the stroke simulator according to claim 4 or 5,
The spring member is set so as to obtain a characteristic that maximizes the pedal reaction force,
The control means is a means for driving the actuator in a direction of pulling the spring member with respect to an increase in pedal position, and increasing the amount of pulling the spring member as the pedal speed is slow. . The stroke simulator according to claim 1,
Vehicle speed detecting means for detecting the vehicle speed is provided;
The control means is means for driving the actuator in a direction in which the spring member is compressed after the actuator is once driven in the direction of pulling the spring member in response to an increase in the pedal position during braking in a low-speed traveling state. Stroke simulator characterized by The stroke simulator according to claim 1,
Vehicle speed detecting means for detecting the vehicle speed is provided;
The stroke simulator according to claim 1, wherein the control means is means for driving the actuator in a direction in which the spring member is compressed with respect to an increase in pedal position during braking in a high-speed running state.

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