Dual-motor wiper synchronous control method based on ripple current detection

Abstract

The application discloses a double-motor wiper synchronous control method based on ripple current detection and relates to the technical field of wiper control methods, and comprises the following steps: obtaining the rotation period of a wiper according to the initial position of each circle of the wiper; the wiper comprises a brush motor used for driving rotation, the carbon brush of the brush motor is switched between commutator segments, the instantaneous short circuit of the commutator to the carbon brush generates a ripple current, the total number n of ripples corresponding to a rotation period is obtained through sampling and counting of the current ripple; the rotation period is equally divided by n to obtain the incremental positions of the two wipers respectively, so that the double-motor wipers are kept synchronous. Through the ripple current detection of the wiper motor, the position observation and estimation without a position sensor are realized, and according to the initial position and the incremental position of the ripple current, the effect of conveniently performing double-wiper motor synchronization and anti-collision control is achieved.

Description

Technical Field

[0001] This invention relates to the field of wiper control methods, and in particular to a dual-motor wiper synchronous control method based on ripple current detection. Background Technology

[0002] Existing dual-motor wiper control methods rely on position information obtained from the position sensors of the wiper motors to calculate the speed and position angle of each wiper motor, thereby achieving synchronization of the two wiper motors and preventing interference and collision.

[0003] This method places certain requirements on the wiper motor, requiring it to have a position sensor so that the control unit can obtain the motor's position information. However, traditional wiper motors only have a single reset switch and no real-time feedback position information device, so they cannot provide the controller with a real-time position signal and therefore cannot directly achieve synchronous control. Summary of the Invention

[0004] The purpose of this invention is to provide a dual-motor wiper synchronization control method based on ripple current detection. By detecting the ripple current of the wiper motor, the method enables sensorless position observation and estimation, and realizes dual wiper motor synchronization and anti-collision control based on the initial position and the incremental position of the ripple current.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A method for synchronous control of dual-motor windshield wipers based on ripple current detection includes the following steps: The rotation cycle of the wiper is obtained based on the initial position of each wiper revolution. The wiper includes a corresponding brushed motor for driving rotation. The carbon brushes of the brushed motor switch between commutator segments. The ripple current generated by the instantaneous short circuit when the commutator contacts the carbon brush is obtained by sampling and counting the current ripple to obtain the total number of ripples n corresponding to one rotation cycle. The rotation cycle is divided into n equal parts to obtain the incremental position of each of the two wipers, thereby controlling the dual-motor wipers to keep them synchronized.

[0006] Furthermore, the initial position is obtained via the wiper reset switch.

[0007] Furthermore, the wiper includes a reduction turbine, and the output end of the brush motor drives the reduction turbine to rotate through a corresponding worm gear. The reduction turbine is connected to the wiper arm.

[0008] Furthermore, the reset switch is connected to the reduction gear, and the position of the reduction gear is used to calibrate the corresponding initial position.

[0009] Furthermore, the wiper also includes a controller for controlling the rotational speed of the brush motor.

[0010] Furthermore, the controller adjusts the speed of the brushed motor in real time through pulse width modulation of the power components.

[0011] Furthermore, the controller adjusts the speed of the brushed motor in real time to control the dual-motor wipers to operate synchronously.

[0012] Furthermore, if the rotation period is l, then the corresponding pulse increment difference Δl = l / n, and the dual-motor wipers operate synchronously, corresponding to a pulse increment differences, then the controller controls the two brushed motors to maintain a pulse increment difference.

[0013] In summary, the present invention has the following beneficial effects: By detecting the ripple current of the wiper motor, position observation and estimation without a position sensor are achieved. Based on the initial position provided by the reset switch and the incremental position of the ripple current, the synchronization and anti-collision control of the dual wiper motors are realized. This realizes the traditional dual-motor synchronous control scheme for wiper motors, achieving the synchronization function without a position sensor. Moreover, it eliminates the need to modify the traditional wiper motor, reduces the electronic circuitry at the motor end, and reduces signal transmission harness issues. Attached Figure Description

[0014] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a simplified electrical connection diagram of a dual-motor wiper synchronous control method based on ripple current detection according to the present invention. Figure 2 This is a schematic diagram of the wiper system in the dual-motor wiper synchronous control method based on ripple current detection of the present invention.

[0016] In the diagram, 1 is the first motor; 2 is the second motor; 3 is the controller; 4 is the scraper arm; and 5 is the scraper blade. Detailed Implementation

[0017] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. These embodiments do not constitute a limitation of the present invention. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this application.

[0018] A method for synchronous control of dual-motor windshield wipers based on ripple current detection, such as... Figure 1 and Figure 2 As shown, it includes the following steps: The rotation cycle of the corresponding wiper is obtained based on the initial position of each wiper revolution. In this embodiment, the two wipers are respectively connected to the first motor 1 and the second motor 2. The wiper includes a reduction turbine. The output end of the brushed motor (first motor 1 or second motor 2) drives the reduction turbine to rotate through the corresponding worm gear. The reduction turbine is connected to the wiper arm 4 through the connecting rod and drives it to rotate. The wiper arm 4 is connected to the wiper blade 5. The initial position is obtained through the wiper's reset switch, which is connected to the reduction turbine. The initial position is calibrated by the position of the reduction turbine (the reset switch effectively calibrates the initial position for each rotation of the reduction turbine; it triggers when the reduction turbine reaches its designated position; one rotation of the reduction turbine corresponds to one reciprocating motion of the wiper arm). For example, a protruding block can be connected to the turbine reduction gear, and a corresponding reset spring can be installed inside the motor as a reset switch. When the protruding part rotates to the spring position, it lifts the spring; each rotation of the reduction turbine has a unique reset position. Figure 1 As shown, when the spring contacts the electric contact, an electrical signal is obtained. This signal can be used to determine the reset position, which is used for motor reset and the limit position of subsequent mechanical installation to ensure that the wiper stops at the reset position. The wiper rotation cycle can also be obtained through other existing technologies.

[0019] like Figure 2 As shown, in this embodiment, the wiper also includes a controller 3 for controlling the rotation speed of the brush motors (first motor 1 and second motor 2). In this embodiment, the controller adjusts the speed of the brush motors in real time to control the dual-motor wipers to run synchronously. The wiper includes a corresponding brushed motor for driving rotation. The carbon brushes of the brushed motor switch between commutator segments. The ripple current generated by the instantaneous short circuit when the commutator contacts the carbon brush is obtained by sampling and counting the current ripple to obtain the total number of ripples n corresponding to one rotation cycle (based on the reset switch trigger time). Divide the rotation cycle into n equal parts to obtain the incremental position change of each of the two wipers. Combined with the initial position, the relative position of the corresponding wipers can be obtained. Thus, the controller 3 adjusts the speed of the two motors in real time through the pulse width modulation (PWM) of the power components to ensure the position synchronization of the two motor wipers and realize the dual closed-loop synchronous control of the speed and position of the two wiper motors. Specifically, in this embodiment, the rotation period is l (which is set as the duration, or can be replaced by the total angle or total length corresponding to one rotation of the wiper), then the corresponding pulse increment difference Δl = l / n. During the operation of the dual-motor wipers, the incremental positions of the two motors are compared in real time. When the dual-motor wipers are running synchronously, there is a pulse increment difference. The controller controls the two brushed motors to maintain a pulse increment difference. For example, when the wiper arms and wiper blades of the dual motors are parallel, there is a difference of n / 2 (i.e., a = n / 2) pulse increment differences. By adjusting the PDI algorithm, the PWM output is changed to adjust the motors in real time to ensure the n / 2 pulse increment difference of the dual motors, thereby achieving synchronous operation of the dual motors and ensuring a collision-free effect. In some embodiments, the real-time position of the corresponding wiper can be obtained directly based on the initial position l0 of the corresponding wiper and the number of ripples that occurred after the last reset switch was triggered, and the wiper can be adjusted accordingly.

[0020] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within the scope of its essence and protection. Such modifications or equivalent substitutions should also be considered to fall within the protection scope of the present invention.

Claims

1. A method for synchronous control of dual-motor windshield wipers based on ripple current detection, characterized in that: Includes the following steps, The rotation cycle of the wiper is obtained based on the initial position of each wiper revolution. The wiper includes a corresponding brushed motor for driving rotation. The carbon brushes of the brushed motor switch between commutator segments. The ripple current generated by the instantaneous short circuit when the commutator contacts the carbon brush is obtained by sampling and counting the current ripple to obtain the total number of ripples n corresponding to one rotation cycle. The rotation cycle is divided into n equal parts to obtain the incremental position of each of the two wipers, thereby controlling the dual-motor wipers to keep them synchronized.

2. The dual-motor wiper synchronous control method based on ripple current detection according to claim 1, characterized in that: The initial position is obtained by resetting the wiper.

3. The dual-motor wiper synchronous control method based on ripple current detection according to claim 2, characterized in that: The wiper includes a reduction turbine, which is driven to rotate by a corresponding worm gear at the output of a brushed motor. The reduction turbine is connected to the wiper arm.

4. The dual-motor wiper synchronous control method based on ripple current detection according to claim 3, characterized in that: The reset switch is connected to the reduction turbine and is used to calibrate the initial position based on the position of the reduction turbine.

5. The dual-motor wiper synchronous control method based on ripple current detection according to claim 1, characterized in that: The wiper also includes a controller for controlling the rotation speed of the brush motor.

6. The dual-motor wiper synchronous control method based on ripple current detection according to claim 5, characterized in that: The controller adjusts the speed of the brushed motor in real time through pulse width modulation of the power components.

7. The method for synchronous control of dual-motor wipers based on ripple current detection according to claim 5 or 6, characterized in that: The controller adjusts the speed of the brushed motor in real time to control the dual-motor wipers to run synchronously.

8. The method for synchronous control of dual-motor wipers based on ripple current detection according to claim 5 or 6, characterized in that: The rotation period is l, which corresponds to a pulse increment difference Δl = l / n. When the dual-motor wipers are running synchronously, there are a pulse increment differences. The controller controls the two brushed motors to maintain a pulse increment difference.

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