KR101627840B1 - A method of setting zero point of bi-directional linear pump for active suspension apparatus - Google Patents

Abstract

The present invention relates to a method for setting a zero point of a bidirectional linear pump which supplies fluid to an actuator connected to a coil spring which is connected to a wheel of a vehicle, comprising: a first step in which an electronic control unit controls at least one among a first valve, disposed between the actuator and the pump, and a second valve, disposed between the pump and a fluid reservoir; a second step of producing a limiting stroke of a piston disposed inside the pump by operating a motor in one direction; a third step of producing a neutral position of the piston based on the limiting stroke of the piston; and a fourth step of moving the piston to the neutral position by operating the motor in the other direction.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of setting a zero point of a bi-directional linear pump applied to an active suspension device,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of setting the origin of a bi-directional linear pump, and more particularly, to a method of setting the origin of a bidirectional linear pump that supplies fluid to an actuator disposed on a wheel of a vehicle in an active suspension system for a vehicle.

An Active Suspension System in a vehicle senses various inputs coming from the road surface through a sensor and an electronic control unit (ECU) controls the roll of the vehicle based on the sensed input. And the like.

Specifically, an actuator for compensating a displacement of a coil spring connected to a wheel of the vehicle is provided, and the amount of fluid supplied to the actuator is appropriately controlled to detect changes in roll and pitch of the vehicle to maintain a constant garage Thereby improving the ride comfort and the road surface force of the vehicle.

Furthermore, the level control (Level Control) of the garage enables the driver to set the height of the garage according to the condition of the road surface, and furthermore, by lowering the garage at high speed to reduce the air resistance, Can be performed.

Regarding such an active suspension system, U.S. Patent No. 6,000,702 discloses a spring and a lift-adjustable regulating unit connected in series, and the flow rate of the fluid supplied to the lift-adjustable regulating unit is controlled by a proportional control valve The contents are disclosed.

However, this technical content has a problem that an expensive proportional control valve and a hydraulic pump must be used. Further, since the hydraulic pump is connected to the engine and is always driven, when the engine is in operation, the pump is always driven, It is necessary to generate an excessive amount of capacity that is not required in the system, and the engine output is reduced, which may adversely affect fuel efficiency.

Further, in the above document, a bidirectional linear pump can be applied to a pump for supplying fluid to the active suspension system, and a technical feature of positioning the piston in the bidirectional linear pump after supplying fluid to one side of the active suspension system There is a problem in that it can not be efficiently coped with the control input.

U.S. Patent No. 6,000,702

In order to solve the above-described problems, a method for setting the origin of a bidirectional linear pump according to an embodiment of the present invention aims to solve the following problems.

By performing the control logic to set the piston position of the bidirectional linear pump to neutral before the main logic for anti-roll control is performed after the ignition signal of the electronic control unit is turned on, Directional linear pump applied to an active suspension system for a vehicle which can efficiently cope with control input.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide an apparatus and method for controlling the same.

A method of setting an origin of a bi-directional linear pump according to an embodiment of the present invention is a method of setting an origin of a bidirectional linear pump that supplies fluid to an actuator connected to a coil spring connected to a wheel of a vehicle, Controlling at least one of a first valve disposed between the pump and the fluid reservoir and a second valve disposed between the pump and the fluid reservoir; A second step of driving the motor in one direction to calculate a limit stroke of the piston disposed in the pump; A third step of calculating a neutral position of the piston based on a limit stroke of the piston; And a fourth step of moving the piston to the neutral position by driving the motor in the other direction.

Wherein the first step comprises controlling the first valve so that the electronic control unit interrupts the movement of fluid between the actuator and the pump and controlling the second valve so as to be in fluid communication between the pump and the fluid reservoir. .

The second step may include a second step of moving the piston stepwise by applying a preset power source to the motor at predetermined intervals, (2-2) detecting the position of the motor rotated during the period; And a second step of calculating a limit stroke of the piston based on the position of the motor.

The step (2-3) further comprises: detecting a first position of the motor and a second position of the motor rotated during a previous cycle, the difference between the first position and the second position being a predetermined value A step 2-3a of comparing with the step of FIG. And determining whether the rotation of the motor is stopped when the difference between the first position and the second position is smaller than a preset value.

In the step 2-3, after the step 2-3b, a predetermined power source is additionally applied to the motor at a predetermined cycle; Comparing the number of times of application of the power source and a preset number of times; And (2-3e) determining that the piston has reached the limit stroke when the number of times of application of the power source is more than a preset number as a result of the comparison in the step 2-3d.

In the third step, it is preferable to further calculate the target position of the motor corresponding to the neutral position of the piston.

The fourth step may include a fourth step (4-1) of gradually moving the piston by applying a predetermined power to the motor at predetermined intervals, Comparing the difference between the position of the motor and the target position; And stopping the application of the power when the difference between the position of the motor and the target position is smaller than a preset value.

It is preferable that the first step to the fourth step are performed after the ignition signal of the electronic control unit is turned on and before the main logic for anti-roll control is started .

A method of setting the origin of a bidirectional linear pump applied to an active suspension device according to an embodiment of the present invention includes calculating a neutral position of a piston using a limit stroke of the piston disposed in the pump and returning the piston to a neutral position based thereon It is possible to expect an effect of more effectively controlling the vehicle active suspension device.

The effects of the present invention are not limited to those mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the following description.

1 is a circuit diagram showing an example of an active suspension system for a vehicle to which a method of setting a origin point of a bidirectional linear pump according to an embodiment of the present invention is applied.
2 and 3 are views showing an example of a bidirectional linear pump according to an embodiment of the present invention.
FIG. 4 is a flowchart illustrating a method of setting an origin of a bi-directional linear pump according to an embodiment of the present invention in a time-series manner.
Figures 5 and 6 are flow charts detailing some of the steps of Figure 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout.

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. It is to be noted that the accompanying drawings are only for the purpose of facilitating understanding of the present invention, and should not be construed as limiting the scope of the present invention with reference to the accompanying drawings.

Hereinafter, a method for setting the origin of a bidirectional linear pump applied to an active suspension device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. FIG. 1 is a circuit diagram showing an example of an active suspension system for a vehicle to which a method of setting a origin point of a bidirectional linear pump according to an embodiment of the present invention is applied. FIGS. 2 and 3 are views showing a bidirectional linear pump according to an embodiment of the present invention. As shown in Fig.

1, an active suspension system for a vehicle according to an embodiment of the present invention may include a pump 100, an actuator 200, a passage, a valve 450, and a fluid reservoir 500 .

The pump 100 is configured to generate a hydraulic pressure in a fluid used in an active suspension system for a vehicle, and adjusts the movement of the fluid in the apparatus. More specifically, the pump 100 is driven using the motor 110. In the prior art, the pump in the active suspension system for a vehicle is connected to the engine as a hydraulic pump and is always driven, thereby generating unnecessary pressure. However, as in the active suspension system for a vehicle according to an embodiment of the present invention, When the structure driven by the motor 110 is adopted, since the electronic control unit (ECU) can selectively drive the pump 100 by transmitting a signal to the motor 110 as needed It is possible to expect an effect of lowering engine power and improving fuel economy.

The actuator 200 receives the fluid from the pump 100 as shown in FIG. 1 and includes first, second, third, and fourth left and right wheels disposed on the left front wheel, the left rear wheel, Third, and fourth actuators 210, 220, 230, and 240, respectively. Each of the actuators 210, 220, 230 and 240 is connected to the coil springs 211, 221, 231 and 241 and the dampers 212, 222, 232 and 242 and in particular to the actuators 210, 220, 230 and 240 Serve to compensate for the displacement of the coil springs 211, 221, 231, and 241

Particularly, the pump 100 may simultaneously supply the fluid to the first actuator 210 and the second actuator 220 based on the driving of the motor 110, or the third actuator 230 and the fourth actuator 240 ) At the same time. 1, the fluid is simultaneously supplied to the actuators on the front and rear wheels of the left wheel of the vehicle by driving one pump 100, or the fluid is simultaneously supplied to the actuators on the front and rear wheels of the right wheel of the vehicle It is possible.

The flow path is a passage for transferring the fluid between the pump 100 and the actuator 200 or the fluid reservoir 500. The flow path formed between the pump 100 and the first actuator 210 is, A first-first flow path 311 directly connected to the pump 100, a first-second flow path 312 branched from the first flow path 311, and a first-third flow path 313, And the first-second flow path 312 is connected to the first actuator 210 and the first-third flow path 313 is connected to the fluid reservoir 500. The flow path connected to the pump 100, the second actuator 220, the third actuator 230, and the fourth actuator 240 can also be subdivided as shown in FIG. 1, like the flow path formed between the first actuators 210 , And a detailed description thereof will be omitted.

A valve is disposed on the flow path 300 to control the flow of the fluid. Particularly, in an active suspension system for a vehicle according to an embodiment of the present invention, an on / off valve is used instead of a proportional control valve, and the operation of the on / off valve is controlled by an electronic control unit So that the movement of the fluid can be selectively controlled. This will simplify the system structure and reduce the cost.

Meanwhile, the fluid reservoir (500, Reservoir) functions to receive and store the fluid when the flow rate of the fluid in the active suspension system for a vehicle is excessive, and furthermore, And supplies the fluid to each of the actuators 200 or the pump 100 when the supply of the fluid is required.

Particularly, the pump 100 may have one chamber and a piston. By providing two cylinders and pistons as shown in FIGS. 2 and 3, it is possible to control the plurality of actuators 200 without increasing the motor output A pump having a dual cylinder structure can be employed. Hereinafter, the present invention will be described with reference to a pump having a dual cylinder structure.

2 and 3, a bidirectional linear pump according to an embodiment of the present invention includes a first rack bar 151 and a second rack bar 152 having a serrated groove formed on one side thereof and a first piston 141, And the pinion 160 are disposed so as to be engaged with the grooves formed on one side of the first rack bar 151 and the second rack bar 152. The pinion 160 is connected to the motor 110. When the pinion 160 is rotated by the motor 110, the first and second rack bars 151 and 152 are opposed to each other Direction. As a result, the first and second pistons 141 and 142 move in opposite directions due to the movement of the first and second rack bars 151 and 152.

With this dual cylinder pump structure, it is possible to simultaneously supply the fluid to the plurality of actuators 200 by one pump 100. Generally, in order to control a plurality of actuators with a single pump, the capacity of the pump must be increased. However, there is a limitation in increasing the pump capacity due to the limit of the motor output. However, in the active suspension system for a vehicle according to an embodiment of the present invention In the case of the pump 100 of the dual cylinder structure, the plurality of actuators 200 can be controlled without increasing the motor output.

The pump 100 of the active suspension system for a vehicle according to an embodiment of the present invention further includes a support yoke 170 supporting at least one of the first rack bar 151 and the second rack bar 152 . The support yoke 170 has a structure in which the first rack bar 151 or the second rack bar 152 and the pinion 160 are employed to prevent the clearance between the first rack bar 151 and the second rack bar 152, It is possible to prevent a malfunction due to wear of a shape corresponding to the groove in the groove or the pinion formed in the pinion, and to prevent the rattle noise due to the occurrence of the clearance.

Referring to FIGS. 4 to 6, a method for setting the origin of a bidirectional linear pump applied to an active suspension device according to an embodiment of the present invention will be described with reference to the above-described vehicle active suspension device and pump applied thereto. . FIG. 4 is a flowchart illustrating a time-series method of setting an origin point of a bidirectional linear pump according to an exemplary embodiment of the present invention, and FIGS. 5 and 6 are flowcharts of sub-steps of FIG.

A method of setting the origin of a bi-directional linear pump applied to an active suspension device according to an embodiment of the present invention is a bi-directional linear pump applied to an active suspension device that supplies a fluid to an actuator 200 connected to a coil spring connected to a wheel of a vehicle. (S100) of maintaining the stroke of the actuator (200), a second step (S200) of calculating the limit stroke of the piston, a step of calculating the neutral position of the piston A third step S300 and a fourth step S400 in which the piston moves to the neutral position.

The first step S100 is a step in which an electronic control unit (ECU) is provided between the actuator 200 and the pump 100 and between the pump 100 and the fluid reservoir 500 And controlling at least one of the disposed second valves 460. Specifically, the electronic control unit controls the first valve 450 so as to block the movement of fluid between the actuator 200 and the pump 100, and to allow fluid communication between the pump 100 and the fluid reservoir 500 It is preferable to control the second valve 460 so that the stroke of the actuator 200 is not affected when the piston 141 is moved to the neutral position, do.

After the first step S100, a second step S200 of driving the motor 110 in one direction to calculate a limit stroke (MAX STROKE) of the piston 141 disposed in the pump 100 is performed. 5, the second step S200 is a second-step S210 (step S210) of gradually moving the piston 141 by a predetermined amount by applying predetermined power to the motor 110 at a predetermined cycle, ), So that it is possible to prevent a sudden movement of the motor. A second step S220 of detecting the position of the motor 110 rotated during the above period and a second step S220 of calculating the limit stroke of the piston 141 based on the detected position of the motor 110 (S230). In particular, step 2-3 (S230) detects a first position of the motor 110 rotated during the current cycle and a second position of the motor 110 rotated during the previous cycle, And step 2-3a (S231) of comparing the difference with a preset value (A). That is, when power is applied to the motor 110 in each cycle, the piston 141 moves in a stepwise direction with a certain amount of increase, so that the positions of the motor in the current cycle and the cycle in the previous cycle are different, When the piston 141 reaches the limit stroke (MAX Stroke), the motor 110 is no longer rotated even when power is further applied to the motor 110, so that the difference between the first position and the second position is 0 or 0 It becomes a close value. If the difference between the first position and the second position is smaller than the preset value A after step 2-3a (S231), it is determined that the rotation of the motor 110 is stopped. At this time, it is preferable that the predetermined value A is determined in consideration of the spacing between the pinion 160 and the rack bars 151 and 152, and the like.

When the rotation of the motor 110 is stopped by the step 2-3b (S232), it can be determined that the piston 141 has reached the limit stroke. However, when the piston 141 does not reach the limit stroke Considering that the rotation of the motor 110 may stop for a moment due to hardware or software reasons, it is preferable that after the step 2-3b (S232) Step S233; And the number of times of application of power is counted. When the number of times of application of additional power is compared with the preset number of times (B), if the number of times of application of power is more than the predetermined number of times (B) It is preferable that steps 2-3d (S234) and step 2-3e (S235) are performed when it is determined that the piston 141 has reached the limit stroke.

A third step S300 of calculating the neutral position 0 of the piston 141 based on the limit stroke of the piston calculated by the second step S200 is performed. The neutral position (0) of the piston 141 is set to a constant since it can be calculated by calculation or test using the limit stroke of the piston. Further, in the third step S300, the target position of the motor 110 corresponding to the neutral position of the piston 141 may be further calculated.

After the third step S300, the fourth step S400 of moving the piston 141 to the calculated neutral position 0 is performed by driving the motor 110 in the other direction. Specifically, as shown in FIG. 6, in step 410 (S410) in which the predetermined power is periodically applied to the motor 110 to move the piston 141 stepwise with a predetermined reduction amount, The piston 141 moves in the opposite direction to the movement direction of the piston 141 in the second step S200. This makes it possible to prevent a sudden movement of the motor. 4-2 (S420) for comparing the difference between the position of the motor 110 and the neutral position of the piston 141 and the target position of the motor 110 corresponding to the position of the motor 110 is performed, If the difference between the target position and the target position is smaller than the predetermined value C, it is determined that the piston 141 is located at the neutral position and the power supply to the motor 110 is stopped in step S430 (S430) .

In particular, considering that the first to fourth steps are preliminary steps for efficiently performing the main logic, after the ignition signal of the electronic control unit is turned on, the anti- It is preferable to perform this before the main logic for control starts.

The embodiments and the accompanying drawings described in the present specification are merely illustrative of some of the technical ideas included in the present invention. Therefore, it is to be understood that the embodiments disclosed herein are not intended to limit the scope of the present invention but to limit the scope of the present invention. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents. It should be interpreted.

100: pump
110: motor
141, 142: piston
200: Actuator
450: first valve
460: second valve
500: Fluid storage

Claims (8)

A method of setting an origin of a bidirectional linear pump (100) applied to an active suspension device for supplying a fluid to an actuator (200) connected to a coil spring connected to a wheel of a vehicle,
An electronic control unit (ECU) includes a first valve 450 disposed between the actuator 200 and the pump 100 and a second valve 450 disposed between the pump 100 and the fluid reservoir 500. [ A first step S100 of controlling at least one of the valves 460;
A second step (S200) of driving the motor (110) in one direction to calculate a limit stroke of the piston (141) disposed inside the pump (100);
A third step (S300) of calculating a neutral position of the piston (141) based on a limit stroke of the piston (141); And
A fourth step (S400) of driving the motor (110) in the other direction to move the piston (141) to the neutral position;
Lt; / RTI >
In the first step S100, the electronic control unit controls the first valve 450 to block fluid movement between the actuator 200 and the pump 100, Wherein the second valve (460) is in fluid communication with the fluid reservoir (500).
delete The method according to claim 1, wherein the second step (S200)
A second step (S210) of gradually moving the piston (141) by applying a predetermined power to the motor (110) at regular intervals;
A second step S220 of detecting the position of the motor 110 rotated during the period; And
A second step (S230) of calculating a limit stroke of the piston 141 based on the position of the motor 110;
Wherein the origin point of the bidirectional linear pump is applied to the active suspension device.
4. The method of claim 3, wherein the step (2-3)
Detects a first position of the motor (110) rotated during the current cycle and a second position of the motor (110) rotated during the immediately preceding cycle, and detects a difference between the first position and the second position by a predetermined value A (Step S231); And
If the difference between the first position and the second position is smaller than a preset value (A), determining (S232) that the rotation of the motor (110) is stopped;
Wherein the origin point of the bidirectional linear pump is applied to the active suspension device.
5. The method of claim 4, wherein the step (2-3)
After the step 2-3b (S232), a predetermined power source is additionally applied to the motor 110 at a predetermined cycle (step S233;
A step 2-3d of comparing the number of times of application of the power source and the preset number of times (B) (S234); And
If it is determined in step S23d that the number of times of application of the power source is equal to or greater than the predetermined number B, step 2-3e is performed in which it is determined that the piston 141 has reached the limit stroke S235);
Further comprising the steps of: determining the origin of the bidirectional linear pump.
The method according to claim 1, wherein, in the third step (S300)
Wherein the target position of the motor (110) corresponding to the neutral position of the piston (141) is further calculated.
7. The method of claim 6, wherein the fourth step (S400)
A fourth step (S410) of gradually moving the piston (141) by applying a predetermined power to the motor (110) at regular intervals;
(S420) comparing the difference between the position of the motor 110 and the target position;
(S430) of stopping the application of power when the difference between the position of the motor 110 and the target position is smaller than a preset value (C);
Wherein the origin point of the bidirectional linear pump is applied to the active suspension device.
The method according to claim 1, wherein the first step (S100) to the fourth step (S400)
The origin of the bi-directional linear pump applied to the active suspension device, which is performed before the ignition signal of the electronic control unit (ECU) is turned on and the main logic for anti-roll control starts, How to set it up.

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