JPH04237644A - Motor control method for power seat and motor control device - Google Patents

Abstract

PURPOSE:To suppress shock at the time of starting/stopping a motor. CONSTITUTION:A current fed to a motor M is PWM-controlled by a MOS type FET 14. After the input of a specified signal to the MOS type FET 14 from a central processing unit 18, the motor M is started under the current value suppressed by PWM control. The moving distance of a movable member in association with the driving of the motor M is previously recognized, and when the movable member reaches a specified position within the moving distance, the current value is suppressed by pulse modulation due to PWM control to decelerate the motor M gradually. After the movable member reaching the stop position, the current supply to the motor M is cut off immediately, and the coil terminal of the motor M is short-circuited by the changeover of the relay contacts RL1a, RL2a of a relay circuit 12, so that the motor M is stopped from its decelerated state under regenerative braking.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention provides a motor control method for a power seat that allows the position of a movable member of a seating posture control device to be arbitrarily adjusted and set according to the body shape and preferences of the occupant by controlling the drive of a motor. and motor control devices.

0002

2. Description of the Related Art For example, in vehicles, seats called power seats are equipped with various seating posture control devices such as seat slide devices, seat lifters, and reclining devices that can be moved by drive control of motors. well known.

[0003] As a motor for such a power seat,
Generally, a DC geared motor (DC motor) is used, and the motor is provided in, for example, a motor control device. The motor is configured to be drive controllable by turning on and off a switch means of a motor control device and switching a relay contact of a motor control relay.

[0004] Here, in a configuration using a DC motor,
Generally, regenerative braking that short-circuits the winding ends of the motor is used to stop the movable member under the regenerative braking of the motor. According to such a configuration, the holding force when stopped, which is a characteristic of a DC motor, can be effectively used, and the stopped state of the motor is reliably maintained under regenerative braking, thereby improving the stopping accuracy of the movable member. is improved.

[0005]

By the way, in a seating posture control device having a movable member having a relatively wide movement range, such as a seat in a seat slide device, rapid movement of the movable member is required. Therefore, in recent years power seats have been designed to increase the rotational speed of the motor.
The high speed rotation of the motor ensures rapid movement of the movable member.

However, in the known configuration, starting or stopping of the motor is controlled by applying or cutting off the supply voltage to the motor as a result of switching on/off of a switch means or switching of a relay contact. ,
Stopping occurs suddenly.

In particular, in a movable member that directly supports the load of a seated person, such as a seat in a seat slide device, the shock when the motor is started or stopped is transmitted to the seated person via the movable member. Therefore, when starting on a seated person,
Gives a shock when stopping. The shock when the motor starts or stops gives a feeling of anxiety to the seated person, and may impair the comfort of the seated person.

[0008]The shock generated when the motor of the seat slide device or the like is started or stopped reduces the sense of stability of the seat, and there is a risk that the seated person may lose their sitting posture.

[0009] Here, the position adjustment of the movable members in the power seat is generally performed after seating and before starting the automobile. However, once the seated person loses his/her sitting posture, it takes time for the seated person to stabilize the seated posture, so it is difficult to start the vehicle immediately after setting the seated posture, and a decrease in operability is unavoidable.

[0010] Furthermore, in a power seat configured to have a ride position that is not obstructed by on-vehicle equipment such as a steering wheel, a seated person moves the seat to the ride position and then gets out of the vehicle. Therefore, if the seated person loses their sitting posture due to the shock when the motor stops,
The seated person must return to their position and then exit the vehicle.
Unable to disembark quickly.

SUMMARY OF THE INVENTION An object of the present invention is to provide a power seat motor control method and a motor control device that suppress shocks when the motor starts and stops.

0012

[Means for Solving the Problem] In order to achieve this object, according to the power seat motor control method of the present invention, the current applied to the motor is controlled by PWM control using an active element. The focus is on the ability to change the rotational speed of the motor without changing the voltage level. After inputting a predetermined signal to the active element, P
The motor is started with a current value suppressed by WM control, and the suppressed current is increased from a minimum value to a maximum value by pulse modulation to gradually accelerate the motor.

[0013]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, in a power seat motor control device 10 according to the present invention, a motor M and relay contacts RL of motor control relays RL1 and RL2 are connected to each other.
1a and RL2a is formed. Then, the motor control device 10 includes a relay circuit 1
2, an active element 14, a switch means 16, and a central processing unit 18, and is configured to be able to drive and control the motor M.

A DC geared motor is normally used as the motor M, and the motor is a movable member of the seating posture control device mounted on the seat 20, for example, as shown in FIG. It is provided as a driving source to slide itself.

In the relay circuit 12, the relay contacts RL1a and RL2a of the motor control relay are interposed between the power supply 24 and the motor M, as can be seen from FIG. , the direction of the motor current Im flowing through the motor, that is, the drive direction of the motor (forward rotation, reverse rotation) can be switched. As the power source 24, a car battery is usually used.

The motor M is driven and controlled under the operation of the switch means 16. The switch means 16 includes, for example, a manual switch 26. As the manual switch 26, for example, an automatic return type seesaw switch having a neutral and two-position contact point, which can change the rotational direction of the motor M depending on the direction of operation, can be used. The manual switch 26 is connected to the central processing unit 18, as shown in FIG.

The central processing unit 18 is formed with a microcomputer (microcomputer) 28, and the microcomputer is configured to process input according to a stored program and to generate appropriate control signals. As can be seen from FIG. 1, the control signal is, for example, relay driver 3
0 and the relay driver outputs motor control relay RL.
1, RL2 is energized. Then, the energized relays among the motor control relays RL1 and RL2 switch the corresponding relay contacts RL1a and RL2a, respectively, thereby controlling the drive of the motor M.

As shown in FIG. 1, the central processing unit 18 and the relay driver 30 are each connected to a battery (power source) 24 of the automobile, and are operated under the voltage supplied from the battery.

[0020]Moreover, the motor M is formed with, for example, a position detecting means 32. As shown in FIG. 1, the position detection means 32 includes, for example, a disk-shaped permanent magnet 34 fixed to the output shaft (not shown) of a motor M, and a reed switch provided adjacent to the side of the permanent magnet. A rotation sensor configured with 36 can be used. In such a configuration, the permanent magnet 34 is connected to the motor M
The polarity of a permanent magnet rotating integrally with the output shaft of the reed switch 36 and passing beside the corresponding reed switch 36 opens and closes the contacts of the reed switch, and when the contacts close, a pulse is generated.

As shown in FIG. 1, the reed switch 36 of the rotation sensor (position detection means) is connected to, for example, the central processing unit 18, and pulses from the rotation sensor are output to the central processing unit. Then, the number of pulses is counted and stored in, for example, a memory (not shown) of the central processing unit 18, and the number of pulses counted determines the number of revolutions of the motor M, that is, the number of rotations of the sheet 20.
position is detected and recognized. The pulse count is, for example, counted up when the motor M rotates forward (when the seat 20 moves forward), and counted down when the motor M rotates in the reverse direction (when the seat moves backward).

[0022] Furthermore, the motor control device 10 includes, for example,
The position of the seat 20 arbitrarily adjusted by operating the manual switch 26 can be stored and reproduced. For example, to memorize and play back seat positions,
Set switch 38 provided as switch means 16
, by the playback switch 40. As shown in FIG. 1, as a set switch 38 and a playback switch 40,
For example, self-resetting push switches may be used, each switch being connected to a central processing unit 18.

In such a configuration, when the set switch 38 is operated at any position of the seat 20, the seat position detected by the number of pulses from the rotation sensor 32 is stored in the central processing unit 18 as a memory position. stored in memory. and,
By operating the playback switch 40 at a position other than the memory position of the seat 20, the contents stored in the memory of the central processing unit 18 are read out, and the memory position of the seat is automatically changed according to the stored contents. Set.

According to such a configuration, it is sufficient to set the seat 20 once to the optimum position for the user by manual control by operating the manual switch 26, so that the user can set the seat 20 to the optimum position for the user without any troublesome operations. can be easily set repeatedly.

The switch means 16 is located at a position where it can be operated by the seated person, for example, as shown in FIG.
The seat cushion 42 is disposed on the side of the seat cushion 42, etc. However, any position that can be operated by the seated person is sufficient, and is not limited to the side of the seat cushion 42, but may be placed in other positions, such as a console box, an armrest on the inner wall of a door, etc.
It is also possible to arrange the switch means 16 in a device (both not shown) or the like.

By the way, the motor control device 10 of the present invention
As shown in FIG. 1, an active element 14 capable of so-called PWF (pulse width modulation) control, which changes the pulse width according to the magnitude of an input signal, is connected to a relay circuit 12.
and is connected to the central processing unit 18. As the active element 14, for example, a MOS type field effect transistor (MOS type FET) can be used.

According to such a configuration, for example, the output signal (drive signal) from the central processing unit 18 is
When input to the MOS type FET (active element) 14, a pulse (drive pulse) having a width corresponding to the magnitude of the drive signal is generated from the MOS type FET. In other words, the so-called switching operation in which the relay circuit 12 is intermittently made conductive by the width of the drive pulse generated in response to the drive signal, and current is intermittently passed through the motor M, is the MOS type FE.
This is done by T14.

[0028] Note that in such a configuration, the MOS
The width of the drive pulse generated from the FET 14 is proportional to the magnitude of the input drive signal. That is, under a small drive signal, the on time of the MOS type FET 14 is short, and under a large drive signal, the on time of the MOS type FET 14 is long.

Further, normally, when the motor M is driven, electrical energy is stored in the motor coil, and the electrical energy is released at the same time as the motor current Im is cut off. Therefore, in the present invention, as can be seen from FIG. 1, the relay circuit 12 is provided with flywheel diodes D1 and D2 that rectify the discharge current Id discharged from the motor coil. Flywheel diode D
1 and D2 are respectively provided so that a discharge current Id flowing in the same direction as the motor current Im flowing by switching the relay contacts RL1a and RL2a flows through the motor M2.

For example, it is assumed that the position of the seat 20 is located at the rear of the memory position stored in the memory of the central processing unit 18 as the initial position. In this state, when the regeneration switch 40 of the switch means is operated, a signal from the central processing unit 18 is output to the relay driver 30, energizing the motor control relay RL1, and as shown in FIG. The corresponding relay contact RL1a is switched.

Further, when the signal from the regeneration switch 40 is input to the central processing unit 18, the current position of the seat 20 is recognized based on the signal from the rotation sensor 32, and the distance from the current position to the memory position is recognized. The required number of rotations of the motor M is calculated and recognized as the moving distance of the seat.

Furthermore, by outputting a signal from the regeneration switch 40 to the central processing unit 18, a drive signal of a predetermined waveform is transmitted from the central processing unit 18 to the MOS FET 14.
The MOS type FET starts a switching operation, makes the relay circuit 12 conductive intermittently, and the motor current Im is intermittently made to flow in the direction of the solid line arrow in FIG.

In the present invention, by varying the drive signal output to the MOS FET 14, the ON time of the MOS FET is gradually increased, and the duty factor of the drive pulse of the MOS FET is minimized. It is configured to gradually increase from the value to the maximum value.

That is, as can be seen from FIGS. 3 and 4, when motor control relay RL1 is energized, the minimum drive pulse corresponding to the drive signal is first generated, and the time corresponding to the width of the pulse is MOS type FET 14 is turned on and current Is flows, and motor M is started by using current Is as motor current Im. MOS type FET 1
Since the current Is flowing through 4 is proportional to the ON time of the MOS FET, the current value is sufficiently suppressed under the minimum drive pulse, and under the suppressed current Im, the motor M is started at low speed, so-called soft start. Then, when motor M is driven,
The seat 20 is slid in the corresponding direction, that is, forward.

[0035] Here, due to the switching operation, MO
When the S-type FET 14 is turned off, the discharge current Id from the motor coil flows to the motor M while forming a loop via the flywheel diode D1, as indicated by the dashed line in FIG. It is continuously driven under the discharge current Id. Note that the current applied to the motor M can be treated equivalently to that driven by the average current of the motor current Im and the discharge current Id, so the rotational speed of the motor does not vary greatly and the motor is driven in a stable state. be done.

After starting the motor M, the central processing unit 1
When the drive signal from 8 is gradually increased, the width of the drive pulse of MOS type FET 14, as shown in FIG.
That is, the on time is gradually increased and the motor M is accelerated. Then, when the duty factor of the drive pulse of the MOS FET 14 reaches the maximum value, the motor M is steadily driven with the width of the drive pulse of the MOS FET kept constant. The transition time from when the motor M 2 is started due to switching of the relay contact RL1a until the motor M 2 is driven steadily is usually about 0.1 seconds.

As described above, according to the power seat motor control method of the present invention, the motor M is not suddenly started at a steady rotational speed, that is, at a steady motor torque, but at a suppressed speed. Since the engine starts at a low temperature and is gradually accelerated to a steady value, the shock at the time of starting the motor, that is, the time of starting the seat 20, is sufficiently suppressed. Therefore, it is possible to perform a so-called soft start of the motor M, and the comfort of the seated person is improved without giving the seated person a sense of anxiety due to a shock when the motor is started.

[0038] Furthermore, since the shock at the time of starting the motor is less likely to be transmitted to the seated person, it is possible to sufficiently suppress the posture of the seated person from collapsing. Therefore, the sitting posture is stabilized, and from this point of view as well, the comfort of the seated person is improved.

By the way, when the playback switch 40 is operated, the current position of the seat 20 is recognized based on the number of pulses from the rotation sensor 32, and the distance traveled to the memory position is calculated. According to the present invention, when the movable member reaches a predetermined position within the moving distance, the on time of the MOS FET 14, that is, the duty factor of the drive pulse, is reduced to suppress the motor current Im. However, the motor M is configured to be gradually decelerated. The predetermined position of the seat 20 at which the motor current Im is suppressed is set, for example, about 3 mm before the memory position.

In such a configuration, when the seat 20 moves forward due to constant driving of the motor M and reaches a predetermined position within the moving distance, the drive signal from the central processing unit 18 causes the MOS type FET 1 to move forward.
The on-time reduction of 4 is started. Then, as shown in FIG. 4, the width of the drive pulse from the MOS FET 14 decreases, and the motor M is gradually decelerated under the suppressed motor current Im.

When the seat 20 reaches the memory position, the signals from the central processing unit 18 and the relay driver 30 are cut off, and the motor control relay RL is activated.
1 is deenergized, relay contact RL1a is switched, and motor M is stopped from the decelerated state. At this time, by switching the relay contact RL1a, the winding terminals of the motor M1 are short-circuited, and the motor is stopped under regenerative braking.

According to the power seat motor control method as described above, at the memory position of the seat 20, the motor M is stopped from a decelerated state rather than from a steady driving state. Therefore, a so-called soft stop of the motor M is possible, and the shock when the motor M is stopped can be sufficiently suppressed, and the seated person will not feel discomfort caused by the shock, and the collapse of the sitting posture can be sufficiently suppressed. Also from this point of view, the comfort of the seated person is improved.

Furthermore, since regenerative braking is applied to the motor M by switching the relay contact RL1a, the seat 20
The seat is reliably stopped at the memory position, the seat stopping accuracy is improved, and the seat is held at the stop position with sufficient holding force.

[0044] Since the seated person's sitting posture can be prevented from collapsing, the sitting posture is stabilized even immediately after the seat 20 is moved. Therefore, it is easy to start the vehicle immediately after setting the seat position and to get off the vehicle immediately after setting the ride position, and the operations when getting on and off the vehicle are not complicated, and getting on and off the vehicle can be done quickly.

Contrary to the embodiment, when the seat 20 is in front of the memory position and the playback switch 40 is operated, the central processing unit 18 and the relay driver 3
By the signal from 0, as shown by the dashed line in Fig. 4,
As motor control relay RL2 is energized,
As shown, the corresponding relay contact RL2a is switched. Then, the motor current Im flows in the direction of the solid line arrow in FIG. 5, and the motor M is started in the reverse direction.

After starting the motor M, as shown in FIG. 4, the motor current I
In addition to m, the discharge current Id from the motor coil is
The current flows in a loop in the relay circuit 12, as indicated by the dashed line, and is driven based on the average value of the motor current and the discharge current. As the drive signal from the central processing unit 18 increases, as shown in FIG. 4, the width of the drive pulse of the MOS FET 14 is gradually expanded, the motor M is gradually accelerated, and the duty of the drive pulse is When the factor reaches its maximum value, keeping the width of the driving pulse constant,
The motor is driven steadily.

Thereafter, when the seat 20 is moved back to a predetermined position within the moving distance due to the reverse rotation of the motor M, a signal from the central processing unit 18 causes the M.O.
The width of the drive pulse of the S-type FET 14 is gradually reduced to decelerate the motor M, and at the memory position of the seat 20, the motor is stopped from the decelerated state.

That is, according to this motor control method, the motor can be soft-started and soft-stopped both when the motor M rotates in the forward direction and in the reverse direction, thereby reliably improving the comfort of the seated person.

[0049] In this embodiment, a configuration is realized in which both a soft start and a soft stop of the motor M can be performed. However, it is not limited to this,
For example, a configuration may be adopted in which at least one of a soft start and a soft stop of the motor M2 is performed.

However, as in the embodiment, motor M
If it is possible to perform both soft start and soft stop, it is possible to suppress the shock when the motor starts and stops, which improves the comfort of the seated person, especially when setting the memory position and ride position of the seat 20. performance is improved.

Furthermore, in the embodiment, the playback switch 4
Although the explanation is given as an example of driving the motor M under the operation of 0, the motor control method of the present invention is not limited to this, and even when the motor is started by operating the manual switch 26. , a soft start of the motor can be obtained. Therefore, even when the manual switch 26 is operated, the shock at the time of starting the motor can be sufficiently suppressed.

According to the power seat motor control device 10 of the present invention, the above-mentioned motor control method can be carried out appropriately, and soft start and soft stop can be ensured to suppress shocks when starting and stopping the motor M. can be obtained. Therefore, the comfort of the seated person is sufficiently improved.

[0053] Then, relay contacts RL1a, RL2a
Since the driving direction of the motor M is switched by switching, the number of components such as the MOS type FET 14 and the flywheel diodes D1 and D2 can be significantly reduced. Therefore, the configuration can be simplified and the motor control device 10 can be inexpensive.
can be easily obtained.

Here, in the embodiment, MOS type F
Although configured to provide PWM control by ET 14, other active devices may be used, such as transistors, but are not limited thereto. however,
If the configuration is configured to perform PWM control using the MOS type FET 14, the motor can be accelerated and decelerated while keeping the voltage applied to the motor at a constant level.
The voltage level burden on the S-type FET is suppressed,
The amount of heat generated by the MOS FET is reduced. Therefore, if the MOS type FET 14 is used, heat dissipation of the active element becomes unnecessary, and the motor control device 10 can be made smaller and lighter, and the configuration can be simplified.

In the embodiment, the seat slide device 18 in which the movable member is the seat 20 is exemplified as a power seat seating posture control device, but the seat slide device 18 is not limited to this, and other seating posture control devices, For example, it goes without saying that the present invention can be applied to reclining devices, seat lifters, and the like.

Further, in the embodiment, the present invention is embodied as a motor control device for a power seat of an automobile. However, any seat that can adjust the position of the movable member of the seating posture control device by controlling the drive of a motor is sufficient, and is not limited to a power seat in a car, but can be used in trains, airplanes, etc.
It can also be applied to seats for ships, etc., and seats for massage, hairdressing, etc.

[0057] The above-described embodiments are for illustrating the present invention, and are not intended to limit the invention in any way.
It goes without saying that all modifications, modifications, etc. made within the technical scope of the present invention are also included in the present invention.

[0058]

[Effects of the Invention] As described above, according to the power seat motor control method according to the present invention, the motor is started or stopped at a speed that is suppressed by PWM control of the current. Therefore, when starting the motor,
The shock that occurs when stopping is sufficiently suppressed. Therefore, the comfort of the seated person is improved without giving the seated person a sense of anxiety caused by shocks when the motor is started or stopped.

Furthermore, since the shock when the motor is started or stopped is not easily transmitted to the seated person, the seated person's posture collapse can be sufficiently suppressed, and the seated posture can be stabilized. Therefore, it is easy to start the vehicle immediately after setting the seat position and to get off the vehicle immediately after setting the ride position, and the operations when getting on and off the vehicle are not complicated, and getting on and off the vehicle can be done quickly.

According to the power seat motor control device of the present invention, the above-mentioned motor control method can be appropriately carried out, and shocks at the time of starting and stopping the motor can be suppressed.
So-called soft start and soft stop can be obtained reliably. Therefore, the comfort of the seated person is sufficiently improved.

Furthermore, since the driving direction of the motor is changed by switching the relay contacts, the number of components such as active elements and flywheel diodes can be significantly reduced. Therefore, the configuration can be simplified and an inexpensive motor control device can be easily obtained.

[0062] In a configuration using a MOS type FET as an active element, the motor can be accelerated and decelerated while keeping the level of voltage applied to the motor constant, so the voltage level burden is suppressed and the active element The amount of heat generated at the Therefore, heat dissipation from active elements is not required, and the motor control device can be made smaller and lighter, and its configuration can be simplified.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a power seat motor control device according to the present invention.

FIG. 2 is a schematic side view of a seat equipped with a seat slide device.

FIG. 3 is an operational diagram of the relay circuit when the motor rotates forward.

FIG. 4 is a time chart according to the power seat motor control method of the present invention.

FIG. 5 is an operational diagram of the relay circuit when the motor is reversed.

[Explanation of symbols]

10 Power seat motor control device 12
Relay circuit 14 Active element (MOS type FET) 16
Switch means 18 Central processing unit 20 Seat (movable member) 22 Seat slide device (seating posture control device)
28 Microcomputer (microcomputer) M
Motor RL1 Motor control relay RL1a Relay contact RL2 Motor control relay RL2a Relay contact

Claims (5)

[Claims] Claim 1: The current supplied to the motor is controlled by an active element while keeping the level of the voltage applied to the motor constant.
After controlling the WM to vary the current value and change the rotational speed of the motor, and inputting a predetermined signal to the active element, PWM
The motor is started with a current value suppressed by control, and the suppressed current is increased from a minimum value to a maximum value by pulse modulation to gradually accelerate the motor.
A method for controlling a power seat motor in which the motor is driven steadily at a steady current value after a predetermined period of time has elapsed. [Claim 2] The current supplied to the motor is controlled by an active element while keeping the level of the voltage applied to the motor constant.
WM Control to vary the current value to change the rotation speed of the motor, recognize in advance the moving distance of the movable member as the motor is driven, and when the movable member reaches a predetermined position within the moving distance, PWM of the current supplied to the motor
The motor is gradually decelerated by suppressing the current value through control pulse modulation, and after the movable member reaches the stop position,
A power seat motor control method that immediately cuts off the supply of current to the motor and short-circuits the winding terminals of the motor to stop the motor from a decelerating state under regenerative braking. [Claim 3] The current supplied to the motor is controlled by an active element while keeping the level of the voltage applied to the motor constant.
After controlling the WM to vary the current value and change the rotational speed of the motor, and inputting a predetermined signal to the active element, PWM
The motor is started with a current value suppressed by control, and the suppressed current is increased from a minimum value to a maximum value by pulse modulation to gradually accelerate the motor.
After a predetermined time has elapsed, the motor is driven steadily under a steady current value, the moving distance of the movable member as the motor is driven is recognized in advance, and when the movable member reaches a predetermined position within the moving distance, The current value is suppressed by pulse modulation using PWM control to gradually decelerate the motor, and after the movable member reaches the stop position, the current supply to the motor is immediately cut off and the motor winding terminals are short-circuited. A power seat motor control method that uses regenerative braking to stop the motor from a decelerating state. 4. A relay having a motor for moving a movable member and a flywheel diode for rectifying a discharge current from a motor coil, the driving direction of the motor being switched by switching the relay contacts of the motor control relay. A circuit and P converting the current supplied to the motor into pulses whose width depends on the magnitude of a given input signal.
WM: an active element that can be controlled; a switch that drives a motor and can adjust and set the position of a movable member;
It is equipped with a central processing unit that processes input information according to a predetermined program and outputs a corresponding predetermined signal to control the drive of the motor. Under PWM control by the element, the voltage applied to the motor is kept at a constant level.
Adjust the current value supplied to the motor to accelerate the motor,
Control the deceleration and under the controlled motor rotation speed,
A power seat motor control device that starts and/or stops a motor. 5. The power seat motor control device according to claim 4, wherein the active element is a MOS type FET.