Power seat control device

Abstract

To provide a control device for a power seat, which can suppress deteriorating of control accuracy in the position of a seat sitting part, which is caused by adjusting of the height of the seat sitting part by rotation of a motor.SOLUTION: A CPU 62 operates a driving circuit 54 of a lift actuator 50 to drive a motor 52 to rotate a link 28 around a vehicle body side joint 30. With this, the height of a seat sitting part 12 is varied. The CPU 62, when determining that a user gets off a vehicle, operates a slide actuator 40 to displace the seat sitting part 12 in a negative x direction, and then operates the lift actuator 50 to lower the seat sitting part 12. At this time, the CPU 62 varies the displacement amount in the x direction and the lowering amount according to the height of the seat sitting part 12 before starting control.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a control device for a power seat.

Background Art

[0002] For example, Patent Document 1 below describes a structure in which a vehicle seat is connected to an upper rail that is relatively displaceable with respect to a lower rail provided on the floor of a vehicle. Further, the seat portion of this seat is rotatably connected to a link that is rotatably connected to the upper rail side. And this link rotates by the power of a motor. When the link rotates, the height of the seat portion changes.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The inventor considered automatically adjusting the height of the seat portion when the user gets out of the vehicle. And it was found that when automatically adjusting the height of the seat portion in the above configuration, the control accuracy of the position of the seat portion may be lowered.

Means for Solving the Problems

[0005] Hereinafter, means for solving the above problems and their effects will be described. 1. A power seat having an auto-lifter for automatically raising and lowering a seat sitting portion of a vehicle is a control target. The auto-lifter includes a link connected to the seat sitting portion via a seat-side joint and connected to a support member via a vehicle-body-side joint, and a motor for rotating the link about the vehicle-body-side joint as a rotation center. The support member is a member provided on the floor portion side of the vehicle rather than the seat sitting portion. When the user gets off the vehicle, a y-direction displacement process for operating the auto-lifter to change a y-coordinate value is executed. The y-coordinate value is a value defining the position of the seat sitting portion in the y direction, which is the vertical direction of the vehicle. The y-direction displacement process includes a rotation amount change process for changing the rotation amount of the motor until the stop of the y-direction displacement process according to the y-coordinate value at the start of the y-direction displacement process. It is a control device for a power seat.

[0006] In the above configuration, the y-coordinate value of the seat sitting portion can be adjusted by rotating the link about the vehicle-body-side joint as a rotation center. Therefore, by changing the y-coordinate value of the seat sitting portion by the motor when the user gets off the vehicle, getting off the vehicle can be assisted. However, the relationship between the rotation amount of the motor and the change amount of the y-coordinate value of the seat sitting portion has non-linearity. Therefore, when the motor at the time of getting off the vehicle is rotated by a predetermined amount, the displacement amount of the seat sitting portion fluctuates depending on the magnitude of the y-coordinate value of the seat sitting portion before getting off the vehicle. That is, the controllability of the position of the seat sitting portion is lowered. Therefore, in the above configuration, the rotation amount of the motor is changed according to the y-coordinate value of the seat sitting portion at the start of the y-direction displacement process, which is a process at the time of getting off the vehicle. Thereby, the fluctuation of the displacement amount of the seat sitting portion caused by the magnitude of the y-coordinate value before getting off the vehicle can be suppressed. Therefore, it is possible to suppress the deterioration of the controllability of the position of the seat sitting portion.

[0007] 2. The y - coordinate value is a value on the y - axis, which is a coordinate axis where the upward direction from the lower side to the upper side of the vehicle is defined as positive. The angle formed between the direction from the rotation center of the body - side joint to the rotation center of the seat - side joint and the positive direction of the y - axis becomes smaller as the y - coordinate value becomes larger. The rotation amount change process is a process of increasing the rotation amount of the motor until the stop of the y - direction displacement process, compared with the case where the y - coordinate value is small when starting the y - direction displacement process, in the power seat control device according to Item 1 above.

[0008] In the case of the above configuration, the amount of change in the y - coordinate value when the motor is rotated by a predetermined amount becomes smaller as the y - coordinate value becomes larger. Therefore, in the above configuration, the rotation amount of the motor is increased compared with the case where the y - coordinate value is small when the y - coordinate value is large. As a result, it is possible to suppress the displacement amount in the y - direction due to the y - direction displacement process from becoming smaller when the y - coordinate value is large than when it is small.

[0009] 3. It includes a storage device in which mapping data is stored. The mapping data includes data defining a first mapping that takes as input a rotation variable value, which is a value of a variable proportional to the net rotation amount of the motor, and outputs the y - coordinate value, and data defining a second mapping that takes the y - coordinate value as input and outputs the rotation variable value. The rotation amount change process includes a rotation variable value acquisition process, a current y - coordinate value calculation process, and a target rotation variable value calculation process. The rotation variable value acquisition process is a process of acquiring the rotation variable value. The current y - coordinate value calculation process is a process of calculating the current y - coordinate value by using the acquired rotation variable value as the input of the first mapping. The current y - coordinate value is the y - coordinate value corresponding to the acquired rotation variable value. The target rotation variable value calculation process is a process of calculating the target rotation variable value by using, as the input of the second mapping, a value obtained by adding a target displacement amount to the current y - coordinate value. The target rotation variable value is the target value of the rotation variable value, in the power seat control device according to Item 1 or 2 above.

[0010] The target rotational variable value can also be calculated by a mapping that takes the current rotational variable value as input and outputs the target rotational variable value. However, in that case, when the displacement amount is different, it is necessary to use different mappings. On the other hand, according to the first mapping and the second mapping described above, the target rotational variable value can be calculated for any combination of the two values of the current rotational variable value and the displacement amount. Therefore, the versatility of the mapping data is high.

[0011] 4. The power seat includes an auto slider that automatically displaces the support member in the longitudinal direction of the vehicle, and when the user gets out of the vehicle, a rear displacement process is executed by operating the auto slider to displace the seat seat portion rearward of the vehicle, and the rear displacement process includes a rear displacement amount change process of changing a rear displacement amount, which is a displacement amount rearward of the vehicle, according to the y coordinate value at the start of the y direction displacement process. The control device for a power seat according to any one of 1 to 3 above.

[0012] In the case of the above configuration, when the y coordinate value is changed by the auto lifter, the seat seat portion also changes in the longitudinal direction of the vehicle. Therefore, in order to displace the seat seat portion rearward by a desired retraction amount when getting out of the vehicle, if the seat seat portion is displaced rearward by an amount equal to the desired retraction amount by the rear displacement process, the control accuracy of the retraction amount when getting out of the vehicle will be low. Also, even if the change amount of the y coordinate value is the same, the displacement amount in the longitudinal direction of the seat seat portion accompanying the y direction displacement process changes according to the y coordinate value at the start of the y direction displacement process. Therefore, if the rear displacement amount by the rear displacement process is shifted by a fixed amount with respect to the desired retraction amount, there is a risk that the control accuracy of the retraction amount when getting out of the vehicle will be low. Therefore, in the above configuration, by changing the rear displacement amount according to the y coordinate value at the start of the y direction displacement process, the retraction amount when getting out of the vehicle can be controlled with high accuracy by the cooperation of the y direction displacement process and the rear displacement process.

[0013] 5. A power seat equipped with an auto-lifter and an auto-slider is the control target. The auto-lifter is a device that includes a link and a motor and automatically raises and lowers the seat seat part of a vehicle. The link is a member that is connected to the seat seat part via a seat-side joint and is connected to a support member via a vehicle body-side joint. The motor rotates the link around the vehicle body-side joint. The auto-slider is a device that automatically displaces the support member in the front-rear direction of the vehicle. When the user gets off the vehicle, it executes a y-direction displacement process and a rearward displacement process. The y-direction displacement process is a process of operating the auto-lifter to change the y-coordinate value when the user gets off the vehicle. The y-coordinate value is a value that defines the position of the seat seat part in the up-down direction of the vehicle. The rearward displacement process is a process of operating the auto-slider to displace the seat seat part rearward in the vehicle, and includes a rearward displacement amount change process of changing the rearward displacement amount, which is the amount of displacement of the vehicle rearward, according to the y-coordinate value at the start of the y-direction displacement process. It is a control device for a power seat.

[0014] In the case of the above configuration, when the y-coordinate value is changed by the auto-lifter, the seat seat part also changes in the front-rear direction of the vehicle. Therefore, if the seat seat part is displaced rearward by an amount equal to the desired retraction amount by the rearward displacement process in order to displace the seat seat part rearward by the desired retraction amount when getting off the vehicle, the control accuracy of the retraction amount when getting off the vehicle will be low. Also, even if the change amount of the y-coordinate value is the same, the displacement amount of the seat seat part in the front-rear direction accompanying the y-direction displacement process changes according to the y-coordinate value at the start of the y-direction displacement process. Therefore, if the rearward displacement amount by the rearward displacement process is shifted by a fixed amount with respect to the desired retraction amount, the control accuracy of the retraction amount when getting off the vehicle may be low. That is, the control accuracy of the position of the seat seat part becomes low. Therefore, in the above configuration, by changing the rearward displacement amount according to the y-coordinate value at the start of the y-direction displacement process, the retraction amount when getting off the vehicle can be controlled with high accuracy by the cooperation of the y-direction displacement process and the rearward displacement process.

[0015] 6. The y - coordinate value is a value on the y - coordinate axis with the positive direction being from the lower side to the upper side of the vehicle. The angle formed between the direction from the rotation center of the body - side joint to the rotation center of the seat - side joint and the positive direction of the y - coordinate axis becomes smaller as the y - coordinate value increases. The backward displacement amount change process is a process of making the absolute value of the difference between the backward displacement amount of the seat seat part at the completion time with respect to before the start of the backward displacement process and the y - direction displacement process and the backward displacement amount larger when the y - coordinate value before the start of the y - direction displacement process is larger than when it is smaller. It is the control device for the power seat according to any one of 4 or 5 above.

[0016] In the case of the above configuration, when the y - coordinate value immediately before displacing the seat seat part by a predetermined amount is larger than when it is smaller, the amount by which the seat seat part is displaced in the front - rear direction of the vehicle due to the displacement by the predetermined amount becomes larger. Therefore, in the above configuration, the absolute value of the difference between the desired backward displacement amount of the vehicle and the backward displacement amount is made larger when the y - coordinate value before the start of the y - direction displacement process is larger than when it is smaller. By setting the backward displacement amount in this way, the displacement in the front - rear direction of the seat seat part by the y - direction displacement process can be compensated by the backward displacement amount.

[0017] 7. The y - direction displacement process is a process of operating the auto - lifter to lower the seat seat part when the user gets off the vehicle. The y - coordinate value becomes smaller as the component in the rear direction of the vehicle in the advancing direction becomes larger. The backward displacement amount change process is a process of making the backward displacement amount smaller when the y - coordinate value before the start of the y - direction displacement process is larger than when it is smaller. It is the control device for the power seat according to 6 above.

[0018] In the above configuration, when the seat portion is lowered, the seat portion is displaced rearward. Moreover, the larger the y-coordinate value is, the larger the amount of rearward displacement of the seat portion due to lowering the seat portion becomes. Therefore, when the amount of rearward displacement by the rearward displacement process is set to a constant value, depending on the y-coordinate value before the start of the y-direction displacement process, the amount of backward movement at the time of getting off the vehicle may become excessively large. Therefore, in the above configuration, when the y-coordinate value before the start of the y-direction displacement process is large, the amount of rearward displacement by the rearward displacement process is made smaller than when it is small. Thereby, the larger the seat portion is displaced rearward due to the y-direction displacement process, the smaller the amount of rearward displacement by the rearward displacement process can be made. Therefore, it is possible to suppress the amount of backward movement at the time of getting off the vehicle from becoming excessively large.

[0019] 8. The y-direction displacement process is a process of operating the auto-lifter to raise the seat portion when the user gets off the vehicle, and the y-coordinate value becomes smaller as the component in the rear direction of the vehicle in the advancing direction becomes larger. The rearward displacement amount change process is the control device for the power seat according to the above 6, which is a process of making the rearward displacement amount larger when the y-coordinate value before the start of the y-direction displacement process is large than when it is small.

[0020] In the above configuration, when the seat portion is raised, the seat portion moves forward. Moreover, the larger the y-coordinate value is, the larger the amount of forward displacement of the seat portion due to raising the seat portion becomes. Therefore, when the amount of rearward displacement is set to a constant value, depending on the y-coordinate value before the start of the y-direction displacement process, the amount of backward movement at the time of getting off the vehicle may become excessively small. Therefore, in the above configuration, when the y-coordinate value before the start of the y-direction displacement process is large, the amount of rearward displacement is made larger than when it is small. Thereby, the larger the seat portion moves forward due to the y-direction displacement process, the larger the amount of rearward displacement can be made. Therefore, it is possible to suppress the amount of backward movement at the time of getting off the vehicle from becoming excessively small.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0022] Hereinafter, an embodiment will be described with reference to the drawings. In the upper left of FIG. 1, a part of the seat 10 of the driver's seat of the vehicle VC is shown enlarged. On the floor part 20 below the seat sitting part 12, a pair of lower rails 22 arranged in parallel are provided. On each lower rail 22, an upper rail 24 that slides on each lower rail 22 is mounted. On each upper rail 24, plate-shaped support members 26 are respectively provided. And the seat sitting part 12 is mechanically connected to the support member 26 via a link 28. Thereby, the seat sitting part 12 can be adjusted in position in the front-rear direction of the vehicle VC by the upper rail 24 sliding on each lower rail 22. In FIG. 1, the front-rear direction of the vehicle VC is described as the x direction. In particular, the positive x direction is the front direction of the vehicle VC.

[0023] The link 28 is mechanically connected to the support member 26 in a rotatable state by a vehicle body side joint 30. Also, the link 28 is mechanically connected to the seat sitting part 12 in a rotatable state via a seat side joint 32.

[0024] Thereby, the seat sitting part 12 can adjust its height. In FIG. 1, the vertical direction of the vehicle VC is described as the y direction. Specifically, the positive y direction is the upward direction of the vehicle VC.

[0025] FIG. 2(a) shows a state where the height of the seat portion 12 is at its maximum. In that case, the direction Dl from the rotation center 30a of the vehicle body side joint 30 to the rotation center 32a of the seat side joint 32 is parallel to the y direction. FIG. 2(b) shows a state where the height of the seat portion 12 is lower than the state shown in FIG. 2(a). In that case, the angle formed by the direction Dl and the y direction becomes larger than zero. The height of the seat portion 12 increases as the angle formed by the direction Dl and the y direction decreases.

[0026] Returning to FIG. 1, the above-mentioned angle is automatically changed by the lift actuator 40. The above-mentioned angle is an amount proportional to the rotation amount of the motor 42. A mechanism for converting the power of the motor 42 into the rotation of the link 28 can be configured to include, for example, a sector gear or the like.

[0027] The lift actuator 40 includes a motor 42, a drive circuit 44, and a rotation angle sensor 46. The motor 42 may be, for example, a DC motor. In that case, the drive circuit 44 may be an H-bridge circuit. The rotation angle sensor 46 is a sensor that detects the rotation angle θl of the motor 42. The lift actuator 40 rotates the link 28 with the rotation axis of the vehicle body side joint 30 by the rotational power of the motor 42. That is, in the present embodiment, the auto-lifter AL that automatically adjusts the height of the seat portion 12 includes the lift actuator 40, the vehicle body side joint 30, the link 28, and the seat side joint 32.

[0028] The seat portion 12 is provided with a slide actuator 50. The slide actuator 50 includes a motor 52, a drive circuit 54, and a rotation angle sensor 56. The motor 52 may be, for example, a DC motor. In that case, the drive circuit 54 may be an H-bridge circuit. The rotation angle sensor 56 is a sensor that detects the rotation angle θs of the motor 52. The slide actuator 50 relatively displaces the upper rail 24 with respect to the lower rail 22 by the rotational power of the motor 52. That is, the slide actuator 50 displaces the seat portion 12 in the longitudinal direction of the vehicle VC. Thus, in the present embodiment, the auto slider AS that automatically slides the seat 10 includes the slide actuator 50, the lower rail 22, and the upper rail 24.

[0029] The vehicle VC includes a control device 60. The control device 60 targets the seat portion 12 for control. The control device 60 controls the position in the x direction and the position in the y direction, which are the control amounts of the seat portion 12. At that time, the control device 60 refers to the rotation angles θs, θl and the output signal of the user interface 70. The user interface 70 is a device through which the user inputs an intention regarding the displacement of the seat portion 12. The output signal of the user interface 70 is a signal reflecting the above intention. Further, the control device 60 refers to the detection result of a detachment sensor 72 that detects the attachment and detachment of the seat belt. Further, the control device 60 refers to the output signal of a travel permission switch 74 of the vehicle VC. The travel permission switch 74 is a switch that places the vehicle VC in a travelable state. For example, when the thrust generation device of the vehicle VC is only an internal combustion engine, the travel permission switch 74 can be an ignition switch. Also, for example, when the thrust generation device includes a motor generator, the travel permission switch 74 can be a switch that closes a relay provided between the motor generator and the battery.

[0030] The CPU 62, monitoring IC 64, and storage device 66 included in the control device 60 are communicable with each other via the communication line 68. The monitoring IC 64 is dedicated hardware that maintains power supply even when the CPU 62 is in the off state and detects the net rotation amount of the motors 42 and 52 based on the rotation angles θs and θl.

[0031] The control device 60 executes position control of the seat seating portion 12 by executing commands specified by the seat control program 66a stored in the storage device 66. In particular, when the control device 60 determines that the driver is about to get off, it executes a process of shifting the seat 10 backward and lowering the seat seating portion 12. This is a process to assist the driver in getting off. The vehicle VC according to the present embodiment assumes that the distance between the floor portion 20 and the road surface is large. Therefore, when getting off, the seat seating portion 12 is automatically lowered.

[0032] Fig. 3 shows the procedure of the process related to the position control at the time of getting off. The process shown in Fig. 3 is realized by the CPU 62 repeatedly executing the seat control program 66a, for example, at a predetermined cycle. Hereinafter, the step numbers of each process are represented by numbers preceded by "S".

[0033] In the series of processes shown in Fig. 3, the CPU 62 first determines whether the logical sum of the following conditions (a) and (b) is true (S10). Condition (a): A condition indicating that it is the timing when the driver's seat belt is switched from the fastened state to the unfastened state.

[0034] Condition (b): A condition indicating that it is the timing when the travel permission switch 74 is switched from the on state to the off state. The process of S10 is to determine whether the driver is about to get off the vehicle. When the CPU 62 determines that the logical OR is true (S10: YES), it acquires the lowering amount QD, the backward movement amount QB, and the rotation variable values Va1 and Va2 (S12). Here, the lowering amount QD indicates the amount by which the seat portion 12 is lowered when getting off the vehicle. The lowering amount QD can be selected by the user from two amounts, "standard" and "small amount", by operating the user interface 70. If there is no instruction from the user interface 70 regarding the lowering amount QD, the CPU 62 assumes that "standard" is selected. Also, the backward movement amount QB indicates the amount by which the seat 10 is moved backward when getting off the vehicle. The backward movement amount QB can be selected by the user from two amounts, "standard" and "small amount", by operating the user interface 70. If there is no instruction from the user interface 70 regarding the backward movement amount QB, the CPU 62 assumes that "standard" is selected.

[0035] The rotation variable value Va1 is a variable proportional to the net rotation amount of the motor 42. That is, for example, if two positive rotations and one negative rotation are made, the rotation variable value Va1 becomes a value proportional to the amount of one positive rotation. The rotation variable value Va1 has a one-to-one correspondence with the above direction Dl. The rotation variable value Va1 is calculated by the monitoring IC 64 or the CPU 62 based on the rotation angle θl.

[0036] The rotation variable value Va2 is a variable proportional to the net rotation amount of the motor 52. The rotation variable value Va2 has a one-to-one correspondence with the position of the seat 10 in the front-rear direction. The rotation variable value Va2 is calculated by the monitoring IC 64 or the CPU 62 based on the rotation angle θs. In this embodiment, it is assumed that there is a linear relationship between the rotation amount of the motor 52 and the displacement amount of the seat portion 12 in the x direction. Therefore, hereinafter, for convenience of explanation, it is assumed that the rotation variable value Va2 is quantified to be equal to the displacement amount of the seat portion 12 in the x direction.

[0037] Note that the rotation variable values Va1 and Va2 are stored in the storage device 66 shown in FIG. 1 while being sequentially updated as coordinate variable data 66c. Next, the CPU 62 calculates the current y coordinate value y0 of the seat portion 12 based on the rotation variable value Va1 (S14). The current y coordinate value y0 is the value of a variable indicating the position of the seat portion 12 in the y direction. The current y coordinate value y0 is quantified by the amount of deviation in the y direction from a reference position. The CPU 62 calculates the current y coordinate value y0 using the function data 66b stored in the storage device 66 shown in FIG. 1. That is, the CPU 62 calculates the current y coordinate value y0 as the value of the dependent variable of the function f by substituting the rotation variable value Va1 into the independent variable of the function f.

[0038] The function f defined by the function data 66b is a non-linear function. That is, as shown in FIG. 2, the height of the seat portion 12 is adjusted by the link 28 rotating about the rotation center 30a. Therefore, the relationship between the rotation amount of the link 28 and the rotation amount of the motor 42 and the height of the seat portion 12 is not a linear relationship. Specifically, the height of the seat portion 12 is expressed by a cosine function having as an independent variable the angle formed between the direction Dl shown in FIG. 2 and the positive y direction. Therefore, the height of the seat portion 12 can be expressed by a cosine function having as an independent variable the rotation amount of the link 28 or the rotation amount of the motor 42. Therefore, the function f may be, for example, a function obtained by adding a constant value to a cosine function. However, for simplicity of calculation by the CPU 62, a quadratic function or the like may be used.

[0039] Next, the CPU 62 substitutes the value obtained by subtracting the descent amount QD from the current y coordinate value y0 into the target y coordinate value y* (S16). This process is a process of calculating the target y coordinate value y* by adding the target displacement amount to the current y coordinate value y0. Here, the reason for subtracting the descent amount QD is that, although the positive y direction is upward, the descent amount QD is set as a positive value.

[0040] Then, the CPU 62 calculates a target rotation variable value Va1*, which is a rotation variable value Va1 when the height of the seat portion 12 reaches the target y - coordinate value y* (S18). The CPU 62 calculates the target rotation variable value Va1* using the function g defined by the function data 66b stored in the storage device 66 shown in FIG. 1. That is, the CPU 62 calculates the target rotation variable value Va1* as the value of the dependent variable of the function f by substituting the target y - coordinate value y* into the independent variable of the function g.

[0041] The function g corresponds to the inverse function of the function f. However, it is not always necessary for the function g to be the exact inverse function of the function f. For example, when the function f is a quadratic function, its exact inverse function includes a square root. However, if the operation involving the square root is difficult, the function g may also be approximated by a quadratic function.

[0042] Also, the CPU 62 calculates a current horizontal displacement Δy0, which is the current amount of variation in the x - direction of the seat portion 12 caused by the lift actuator 40 (S20). That is, as shown in FIG. 2, since the position of the seat portion 12 in the x - direction varies according to the angle formed by the direction Dl and the y - direction, the current value of the quantified amount of that variation is the current horizontal displacement Δy0. This amount of variation can be quantified, for example, as the amount of variation in the x - direction of the seat portion 12 when the direction Dl and the y - direction are not parallel compared to when the direction Dl and the y - direction are parallel. Note that the current horizontal displacement Δy0 has a larger value as the x - direction is more positive.

[0043] The CPU 62 calculates the current horizontal displacement Δy0 using the function h defined by the function data 66b stored in the storage device 66 shown in FIG. 1. That is, the CPU 62 calculates the current horizontal displacement Δy0 as the value of the dependent variable of the function h by substituting the rotation variable value Va1 into the independent variable of the function h. The function h is a non-linear function. That is, the relationship between the rotation amount of the link 28 and the rotation amount of the motor 42 and the displacement amount in the x direction of the seat portion 12 caused by the rotation is not a linear relationship. Specifically, the displacement in the x direction of the seat portion 12 caused by the rotation is expressed by a sine function having as the independent variable the angle formed by the direction Dl shown in FIG. 2 and the positive y direction. Therefore, the displacement in the x direction of the seat portion 12 can be expressed by a sine function having the rotation amount of the link 28 or the rotation amount of the motor 42 as the independent variable. The function h may be, for example, a function obtained by adding a constant value to a sine function. However, in order to simplify the calculation by the CPU 62, a quadratic function or the like may be used, for example.

[0044] Further, the CPU 62 calculates, using the function h, a post-movement horizontal displacement Δy1, which is a value corresponding to the target rotation variable value Va1*, with respect to the amount of variation in the x direction of the seat portion 12 caused by the lift actuator 40 (S22). The post-movement horizontal displacement Δy1 becomes a larger value as the positive x direction.

[0045] Then, the CPU 62 substitutes, into the horizontal error ΔΔy, the value obtained by subtracting the current horizontal displacement Δy0 from the post-movement horizontal displacement Δy1 (S24). The horizontal error ΔΔy is the amount by which the seat portion 12 is displaced rearward by lowering the seat portion 12 by the lowering amount QD. Note that the horizontal error ΔΔy is a negative value.

[0046] Next, the CPU 62 substitutes, into the target horizontal position Va2*, a value obtained by subtracting from the rotational variable value Va2 on the side of the slide actuator 50 a value obtained by adding the horizontal error ΔΔy to the retraction amount QB (S26). The target horizontal position Va2* indicates the amount by which the seat portion 12 is to be retracted by the slide actuator 50 in order to retract the seat portion 12 by the retraction amount QB. That is, since the seat portion 12 retracts by |ΔΔy| when the seat portion 12 is lowered by the lowering amount QD, the slide actuator 50 translates the seat portion 12 by a value obtained by reducing the retraction amount QB by |ΔΔy|.

[0047] Then, the CPU 62 operates the auto slider AS to control the rotational variable value Va2 to the target horizontal position Va2* (S28). Specifically, the CPU 62 operates the drive circuit 54 of the slide actuator 50 to rotate the motor 52 until the rotational variable value Va2 becomes the target horizontal position Va2*. Next, the CPU 62 operates the auto lifter AL to lower the seat portion 12 by the lowering amount QD (S30). In other words, the CPU 62 operates the drive circuit 44 of the lift actuator 40 to rotate the motor 42 until the rotational variable value Va1 becomes the target rotational variable value Va1*.

[0048] Note that when the CPU 62 completes the process of S30 and when a negative determination is made in the process of S10, the CPU 62 once terminates the series of processes shown in FIG. 3. Here, the operations and effects of the present embodiment will be described.

[0049] When the driver gets off the vehicle, the CPU 62 calculates the current y - coordinate value y0 by inputting the current rotation variable value Va1 into the function f. Then, the CPU 62 calculates the target rotation variable value Va1* by inputting the value obtained by subtracting the descent amount QD from the current y - coordinate value y0 into the function g. And the CPU 62 controls the rotation variable value Va1 to the target rotation variable value Va1*. Here, the absolute value of the difference between the rotation variable value Va1 and the target rotation variable value Va1* is larger when the current y - coordinate value y0 is large than when it is small. In other words, the rotation amount of the motor 42 for descending by the descent amount QD is larger when the current y - coordinate value y0 is large than when it is small. This is because the y - coordinate value can be expressed by a cosine function with the angle formed by the direction Dl shown in FIG. 2 and the positive y - direction as the independent variable. That is, in the range where the above - mentioned angle is from 0 degrees to 90 degrees, the second - order differential value of the cosine function is a negative value. Therefore, in this range, the absolute value of the decreasing speed of the cosine function gradually increases.

[0050] In this way, by increasing the rotation amount of the motor 42 when the current y - coordinate value y0 is large compared to when it is small, the seat seat part 12 can be lowered by the descent amount QD regardless of the magnitude of the current y - coordinate value y0.

[0051] Furthermore, when the driver gets off the vehicle, the CPU 62 retracts the seat seat part 12 as follows. FIG. 4 illustrates the process when the driver gets off the vehicle. FIG. 4(a) shows the case where the height of the seat seat part 12 before getting off is set high, while FIG. 4(b) shows the case where the height of the seat seat part 12 before getting off is set low. In FIG. 4, for the sake of convenience of explanation, both ends of the lower rail 22 in the x - direction are shown at the same positions as both ends of the seat seat part 12 in the x - direction before getting off. However, this does not mean that the length of the lower rail 22 is actually the same as the length of the seat seat part 12.

[0052] The rear displacement amount Δ1 of the seat seat part 12 by the slide actuator 50 shown in FIG. 4(a) is smaller than the rear displacement amount Δ2 of the seat seat part 12 by the slide actuator 50 shown in FIG. 4(b).

[0053] This is because the height of the seat portion 12 before getting off the vehicle is higher in the case of FIG. 4(a) than in the case of FIG. 4(b). That is, the absolute value of the horizontal error ΔΔy when the seat portion 12 is lowered by the lowering amount QD becomes larger as the seat portion 12 is lowered from a higher height state. This is because the displacement amount of the seat portion 12 in the x direction accompanying the lowering of the seat portion 12 can be expressed by a sine function having as an independent variable the angle formed by the direction Dl shown in FIG. 2 and the positive y direction. That is, in the range where the above-mentioned formed angle is from 0 degrees to 90 degrees, the second derivative value of the sine function becomes a negative value. Therefore, the increasing speed of the displacement amount of the seat portion 12 in the x direction accompanying the lowering of the seat portion 12 becomes smaller as the height of the seat portion 12 before getting off the vehicle is lower.

[0054] Therefore, the higher the height of the seat portion 12, the smaller the backward displacement amount of the seat portion 12 by the slide actuator 50, so that the final backward movement amount of the seat portion 12 by the process at the time of getting off the vehicle can be controlled to the desired backward movement amount QB.

[0055] According to the present embodiment described above, the following operations and effects can be obtained. (1) Based on the functions f and g, the target rotation variable value Va1* was calculated. When the lowering amount QD is determined in two ways, the target rotation variable value Va1* can also be calculated by providing two mappings that output the target rotation variable value Va1* with the current rotation variable value Va1 as an input. However, in that case, when there is a change in the lowering amount QD, it is necessary to change the mapping itself. Also, for example, when the magnitude of the lowering amount QD differs for each vehicle type, it is necessary to create mappings individually for each vehicle type. In contrast, according to the functions f and g, the target rotation variable value Va1* can be calculated for any combination of the two values of the current rotation variable value Va1 and the lowering amount QD. Therefore, the versatility of the function data 66b is high.

[0056] <Corresponding relationship> The correspondence between the matters in the above-described embodiment and the matters described in the column of "Means for Solving the Problems" is as follows. Below, the correspondence is shown for each number of the solution means described in the column of "Means for Solving the Problems". [1] The auto-lifter corresponds to the auto-lifter AL. The motor corresponds to the motor 42. The y-direction displacement process corresponds to the processes of S12 to S18 and S30. The rotation amount change process corresponds to the processes of S12 to S18. [2] The direction of advancing toward the rotation center corresponds to the direction Dl. [3] The storage device corresponds to the storage device 66. The mapping data corresponds to the function data 66b. The rotation variable value acquisition process corresponds to the process of S12. The rotation variable value corresponds to the rotation variable value Va1. The current y-coordinate value calculation process corresponds to the process of S14. The target displacement amount corresponds to the value obtained by multiplying the lowering amount QD by "-1". The target rotation variable value calculation process corresponds to the processes of S16 and S18. [4] The auto-slider corresponds to the auto-slider AS. The backward displacement process corresponds to the processes of S20 to S28. [5] The auto-lifter corresponds to the auto-lifter AL. The motor corresponds to the motor 42. The auto-slider corresponds to the auto-slider AS. The y-direction displacement process corresponds to the processes of S12 to S18 and S30. The backward displacement amount change process corresponds to the processes of S20 to S26. [6] It corresponds to the process shown in FIG. 4 and the modification example of the above-described embodiment, FIG. 5. [7] It corresponds to the process shown in FIG. 5. [8] It corresponds to the process shown in FIG. 5, which is a modification example of the above-described embodiment.

[0057] <Other Embodiments> Note that this embodiment can be implemented with the following modifications. This embodiment and the following modification examples can be implemented in combination with each other within a technically non-conflicting range.

[0058] "Regarding the Lowering Amount" ·In the above-described embodiment, the lowering amount QD can be set in a binary manner by operating the user interface 70, but it is not limited to this. For example, it may be possible to set it to three or more different values. However, it is not essential that the user can adjust the magnitude of the lowering amount QD.

[0059] "Regarding the mapping data" · The mapping data that defines the first mapping with the rotation variable value Va1 as the input variable and the y - coordinate value as the output variable, and the second mapping with the y - coordinate value as the input variable and the rotation variable value Va1 as the output variable is not limited to the function data 66b. For example, it may be map data that takes either one of the two, the rotation variable value Va1 and the y - coordinate value, as the input variable and the other as the output variable. In that case, in the process of S14, the rotation variable value Va1 may be used as the input variable, while in the process of S18, the y - coordinate value may be used as the input variable. Note that map data is a set of data consisting of discrete values of the input variable and the values of the output variable corresponding to each value of the input variable. Also, for the map operation when the value of the input variable matches any of the values of the input variable of the map data, for example, the process may be to take the value of the output variable of the corresponding map data as the operation result. Also, for example, for the map operation when they do not match, the process may be to take the value obtained by interpolating the values of a pair of output variables included in the map data as the operation result.

[0060] "Regarding the y - direction displacement process" · It is not limited to the process of lowering the seat seat part 12 when getting off the vehicle, and it may also be a process of raising it. The process in that case is illustrated in FIG. 5.

[0061] FIG. 5(a) shows the case where the height of the seat seat part 12 before getting off the vehicle is set high, while FIG. 5(b) shows the case where the height of the seat seat part 12 before getting off the vehicle is set low. Note that in FIG. 5, for convenience of explanation, both ends of the lower rail 22 in the x - direction are shown at the same positions as both ends of the seat seat part 12 in the x - direction before getting off the vehicle. However, this does not mean that the length of the lower rail 22 is actually the same as the length of the seat seat part 12.

[0062] The backward displacement amount Δ3 of the seat portion 12 by the slide actuator 50 shown in Fig. 5(a) is larger than the backward displacement amount Δ4 of the seat portion 12 by the slide actuator 50 shown in Fig. 5(b). This is in view of the fact that the higher the height of the seat portion 12 before getting off the vehicle, the larger the amount by which the seat portion 12 is displaced forward in the x direction when the seat portion 12 is raised by the raising amount QU. The process shown in Fig. 5 can be realized by substituting the process of S16 in Fig. 3 with the process of substituting the value obtained by adding the raising amount QU to the current y coordinate value y0 for the target y coordinate value y*.

[0063] "Regarding the rotation amount change process" · It is not essential to calculate the target rotation variable value Va1* using the current rotation variable value Va1 as an input. For example, as the coordinate variable data 66c, the current y coordinate value y0 may be stored in the storage device 66, and the target rotation variable value Va1* may be calculated using the current y coordinate value y0 as an input.

[0064] "Regarding the backward displacement amount change process" · It is not essential to calculate the target horizontal position Va2* using the current rotation variable value Va1 as an input. For example, as the coordinate variable data 66c, the current y coordinate value y0 may be stored in the storage device 66, and the target horizontal position Va2* may be calculated using the current y coordinate value y0 as an input.

[0065] "Regarding the execution order of the y-direction displacement process and the backward displacement process" · It is not essential to execute the y-direction displacement process after the execution of the backward displacement process. That is, the backward displacement process may be executed after the execution of the y-direction displacement process.

[0066] "Regarding the auto-lifter and the auto-slider" · The auto-lifter AL is not limited to the configuration in which the seat portion 12 descends when the link 28 rotates so that the direction Dl shown in Fig. 2 has a negative x-direction component from the state where it is parallel to the y direction. For example, it may be configured such that the seat portion 12 descends when the link 28 rotates so that the direction Dl shown in Fig. 2 has a positive x-direction component from the state where it is parallel to the y direction.

[0067] · It is not essential that the slide actuator 50 be arranged on the seat portion 12. For example, it may be arranged at a position sandwiched between a pair of support members 26. · It is not essential that the lift actuator 40 be arranged on the seat portion 12. For example, it may be arranged at a position sandwiched between a pair of support members 26.

[0068] · It is not essential that the motor 42 provided in the lift actuator 40 and the motor 52 provided in the slide actuator 50 be separate. For example, the motor 42 provided in the lift actuator 40 and the motor 52 provided in the slide actuator 50 may be a shared single motor. In that case, the lift actuator 40 and the slide actuator 50 may be configured to include a power transmission path and a switching device. Here, the power transmission device includes a path for converting the power of a single motor into power for rotating the link 28 and a path for converting the power of a single motor into power for displacing the upper rail 24. The switching device is a device for selecting either one of the above two paths as the path for actually transmitting the power of the motor.

[0069] "Regarding the power seat" · The power seat to which the above control and the control of its modification examples are applied is not limited to the driver's seat.

[0070] · It is not essential that the power seat include both the lift actuator 40 and the slide actuator 50. It may include only the lift actuator 40. "Regarding the control device" ·The control device is not limited to one that includes a CPU and a storage device and executes software processing. For example, at least a part of what was software-processed in the above embodiment may be provided with a dedicated hardware circuit such as an ASIC that performs hardware processing. That is, the control device may have any of the following configurations (a) to (c). (a) It includes a processing device that executes all of the above processing according to a program, and a program storage device that stores the program. (b) It includes a processing device and a program storage device that execute a part of the above processing according to a program, and a dedicated hardware circuit that executes the remaining processing. (c) It includes a dedicated hardware circuit that executes all of the above processing. Here, there may be a plurality of software execution devices including a processing device and a program storage device, and dedicated hardware circuits.

Explanation of Signs

[0071] 12…Sheet seating part 20…Floor part 22…Lower rail 24…Upper rail 26…Support member 28…Link 30…Vehicle body side joint 30a…Rotation center 32…Seat side joint 32a…Rotation center 40…Lift actuator 42…Motor 44…Drive circuit 50…Slide actuator 52…Motor 54…Drive circuit 60…Control device

Claims

1. A power seat including an auto-lifter for automatically raising and lowering a seat sitting portion of a vehicle is a control target, The auto-lifter includes a link connected to the seat sitting portion via a seat side joint and connected to a support member via a vehicle body side joint, and a motor for rotating the link about the vehicle body side joint as a rotation center, The support member is a member provided on the floor portion side of the vehicle rather than the seat sitting portion, When the user gets off the vehicle, a y-direction displacement process for operating the auto-lifter to change the y-coordinate value is executed, The y-coordinate value is a value that defines the position of the seat sitting portion in the y-direction, which is the vertical direction of the vehicle, The y-direction displacement process includes a rotation amount change process for changing the rotation amount of the motor until the stop of the y-direction displacement process according to the y-coordinate value at the start of the y-direction displacement process, A storage device storing mapping data is provided, The mapping data includes data defining a first map having a rotation variable value, which is a value of a variable proportional to the net rotation amount of the motor, as an input and the y-coordinate value as an output, and data defining a second map having the y-coordinate value as an input and the rotation variable value as an output, The rotation amount change process includes a rotation variable value acquisition process, a current y-coordinate value calculation process, and a target rotation variable value calculation process, The rotation variable value acquisition process is a process for acquiring the rotation variable value, The current y-coordinate value calculation process is a process for calculating the current y-coordinate value using the acquired rotation variable value as an input to the first map, The current y-coordinate value is the y-coordinate value corresponding to the acquired rotation variable value, The target rotation variable value calculation process is a process for calculating a target rotation variable value by using, as an input to the second map, a value obtained by adding a target displacement amount to the current y-coordinate value, The target rotation variable value is a control device for a power seat that is a target value of the rotation variable value.

2. The y-coordinate value is a value on a y-coordinate axis that is a coordinate axis with the side advancing from the lower side to the upper side of the vehicle being positive, The angle formed by the direction from the rotation center of the vehicle body side joint to the rotation center of the seat side joint and the positive direction of the y-coordinate axis becomes smaller as the y-coordinate value becomes larger. The rotation amount change process is a process of increasing the rotation amount of the motor until the stop of the y-direction displacement process, as compared with the case where the y-coordinate value at the start of the y-direction displacement process is large. The control device for a power seat according to claim 1.

3. The power seat includes an auto slider that automatically displaces the support member in the front-rear direction of the vehicle. When the user gets out of the vehicle, a rearward displacement process is executed by operating the auto slider to displace the seat seat portion rearward of the vehicle. The rearward displacement process includes a rearward displacement amount change process of changing a rearward displacement amount, which is a displacement amount rearward of the vehicle, according to the y-coordinate value at the start of the y-direction displacement process. The control device for a power seat according to claim 1 or 2.

4. The y-coordinate value is a value on the y-coordinate axis, which is a coordinate axis with the upward direction from the lower side to the upper side of the vehicle being positive. The angle formed between the direction from the rotation center of the vehicle body side joint to the rotation center of the seat side joint and the positive direction of the y-coordinate axis becomes smaller as the y-coordinate value becomes larger. The rearward displacement amount change process is a process of making the absolute value of the difference between the backward movement amount of the seat seat portion at the completion of the rearward displacement process and the y-direction displacement process with respect to before the start of the rearward displacement amount and the rearward displacement amount larger than when the y-coordinate value at the start of the y-direction displacement process is large. The control device for a power seat according to claim 3.

5. A power seat including an auto lifter and an auto slider is a control target. The auto lifter includes a link and a motor, and is a device that automatically raises and lowers the seat seat portion of the vehicle. The link is a member that is connected to the seat seat portion via a seat side joint and is connected to a support member via a vehicle body side joint. The motor rotates the link with the vehicle body side joint as the rotation center. The auto slider is a device that automatically displaces the support member in the front-rear direction of the vehicle. When the user gets out of the vehicle, a y-direction displacement process and a rearward displacement process are executed. The y-direction displacement process is a process of changing the y-coordinate value by operating the auto lifter when the user gets out of the vehicle. The y-coordinate value is a value that defines the position of the seat seat portion in the up-down direction of the vehicle. The rearward displacement process is a process of operating the auto slider to displace the seat seating portion rearward of the vehicle, and includes a rearward displacement amount change process of changing a rearward displacement amount, which is an amount of displacing the vehicle rearward, according to the y coordinate value at the start of the y-direction displacement process. The y coordinate value is a value on the y coordinate axis, which is a coordinate axis with the upward direction from the lower side to the upper side of the vehicle being positive. The angle formed between the direction from the rotation center of the vehicle body side joint to the rotation center of the seat side joint and the positive direction of the y coordinate axis becomes smaller as the y coordinate value becomes larger. The rearward displacement amount change process is a process of making the absolute value of the difference between the rearward movement amount of the seat seating portion at the completion with respect to before the start of the rearward displacement process and the y-direction displacement process and the rearward displacement amount larger when the y coordinate value at the start of the y-direction displacement process is larger than when it is smaller, for a power seat control device.

Images