An overcurrent detection type window anti-pinch device and method

Abstract

The present invention relates to the technical field of vehicle control, and specifically discloses an overload current detection type window anti-pinch device with a small motor volume and simple wiring, including a motor; a sampling resistor for motor detection; a filtering circuit; an amplifying circuit and a processing circuit for signal processing and controlling the motor; the processing circuit includes an MCU processor, a forward rotation control loop and a reverse rotation control loop. The MCU processor is connected to the reference ground through the switch K1. When K1 is closed, the MCU processor sends a forward or reverse step signal to the motor, reads the sampling level Vs and stores the number of pulses, and also stores the number of pulses Pm from the lowest to the highest end of the window; the MCU processor is connected to the switches K2 and K3 corresponding to triggering the forward and reverse rotation control loops to work; when the sampling voltage value Vx obtained by the MCU processor when K2 or K3 is closed is greater than Vs and the number of pulses is less than Pm, the motor is controlled to reverse to move the window away from the obstacle; a method corresponding to the device is also included.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle control, and particularly to an overcurrent detection type window anti-pinch device and method. Background Art

[0002] The use of electric windows has reduced the control difficulty of automobile windows and promoted the intelligent development of automobiles. However, in the electric control process of automobile windows, due to the lack of induction devices, the windows often pinch passengers by mistake, and in more serious cases, the pinched person may even die. Therefore, it is particularly necessary to prevent the windows from pinching passengers to improve the safety of automobile use. At present, there are mainly two window anti-pinch solutions. One is to install a sensor at the window end to identify whether there is an obstacle when closing the window; the other is to install a camera around the window to monitor whether there is an obstacle above the window and detect the situation above the window first when closing the window. The former ensures that the obstacle will not be pinched, with high safety, but it is prone to misoperation and has unstable performance; the latter solution has a relatively high cost and is difficult to popularize.

[0003] In view of this, in order to improve the reliability of window control, in the solution of installing a sensor, the Hall sensor technology is mainly adopted. The Hall sensor technology is mature, the circuit processing is simple, and the recognition is accurate. However, in the above solution, a Hall sensor needs to be added inside the motor. In this way, the volume of the motor and the design difficulty will be increased, and it is difficult to meet the market demand for the miniaturization of the motor; in addition, 3 connecting wires for connecting the Hall sensor need to be added in this design solution, resulting in complex wiring inside the motor, increasing the wiring difficulty and cost of the automobile, and restricting the optimized design of the automobile. Summary of the Invention

[0004] Based on this, in view of the technical problems of the large volume of the motor and the complex wiring, it is necessary to provide an overcurrent detection type window anti-pinch device and method with a small motor volume and simple vehicle wiring.

[0005] An overcurrent detection type window anti-pinch device, the device includes a motor electrically connected to an on-vehicle power supply for driving the window to move; a sampling resistor connected in series with the motor and grounded for motor ripple detection; a filtering circuit for filtering out interference signals in the signals sent by the sampling resistor; an amplifying circuit for amplifying the signals sent by the filtering circuit; and a processing circuit for signal processing and feedback control of the motor;

[0006] The processing circuit includes an MCU processor and a control loop for controlling the forward and reverse rotation of the motor. The P2.3 pin of the MCU processor is electrically connected to the reference ground through the on-off key K1. The MCU processor is used to send a forward stepping signal or a reverse stepping signal to the motor when the on-off key K1 is closed, read the sampled level Vs sent by the amplification circuit, process it, and store it as the number of pulses. The MCU processor is also used to store the number of pulses Pm when the mapped window position moves from the highest end to the lowest end; the control loop includes a forward rotation control loop electrically connected to the P2.1 pin of the MCU processor and a reverse rotation control loop electrically connected to the P2.0 pin of the MCU processor. The P2.2 pin of the MCU processor is connected to the on-off key K2 for triggering the operation of the forward rotation control loop, and the P2.4 pin of the MCU processor is connected to the on-off key K3 for triggering the operation of the reverse rotation control loop;

[0007] When the sampled voltage value Vx obtained by the MCU processor when the on-off key K2 or the on-off key K3 is closed is greater than the sampled level Vs, and the processed number of pulses is less than the number of pulses Pm, the MCU processor controls the operation of the reverse rotation control loop through the P2.0 pin to control the motor to move the window away from the obstacle.

[0008] In one embodiment, the MCU processor is a data acquisition chip or / and a single-chip microcomputer of model ADuC81.

[0009] In one embodiment, when the MCU processor is a data acquisition chip of model ADuC81, the filtering circuit is a low-pass filter for providing a mixed AC and DC signal.

[0010] In one embodiment, a clock circuit connected to the MCU processor is further included.

[0011] In one embodiment, when the MCU processor is a single-chip microcomputer, the filtering circuit includes a high-pass and a low-pass filter for providing an AC signal.

[0012] In one embodiment, the device further includes a comparison circuit for processing the signal amplified by the amplification circuit and converting the ripple signal into a PWM signal for the MCU processor to detect.

[0013] In one embodiment, the device further includes a motor drive current detection circuit connected to the reverse rotation control loop. The motor drive current detection circuit includes a resistor R1, a capacitor C1 respectively connected to the reference ground, and a resistor R2 provided between the resistor R1 and the capacitor C1. The resistor R1 is also connected to the forward rotation control loop.

[0014] In one embodiment, the forward rotation control circuit is formed by connecting a motor, MOS transistor T1, MOS transistor T2, and MOS transistor T4 in series, and the reverse rotation control circuit is formed by connecting a motor, MOS transistor T1, MOS transistor T2, and MOS transistor T3 in series.

[0015] The present invention also discloses an overload current detection type window anti-pinch method. The device used in this method includes a motor electrically connected to a vehicle power supply for driving the window to move; a sampling resistor connected in series with the motor and grounded for motor ripple detection; a filtering circuit for filtering out interference signals in the signal sent by the sampling resistor; an amplifying circuit for amplifying the signal sent by the filtering circuit; and a processing circuit for signal processing and feedback control of the motor. The processing circuit includes an MCU processor, a forward rotation control circuit electrically connected to the P2.1 pin of the MCU processor, and a reverse rotation control circuit electrically connected to the P2.0 pin of the MCU processor. The P2.3 pin of the MCU processor is electrically connected to the reference ground through a switch key K1. The MCU processor is also connected with a switch key K2 for triggering the forward rotation control circuit to work and a switch key K3 for triggering the reverse rotation control circuit to work.

[0016] This method includes the following steps:

[0017] S1: When the switch key K1 is closed, the MCU processor sends a forward step signal to the motor and reads the sampled level VS during the operation of the motor until the window moves to the positive top end; the MCU processor sends a reverse step signal to the motor until the window moves to the negative bottom end, reads the number of pulses Pm of the step signal and stores it in the EPROOM as the standard number of pulses.

[0018] S2: The MCU processor detects the opening and closing states of the switch key K2 and the switch key K3. When it detects that the switch key K2 is closed, the MCU processor controls the motor to rotate forward to raise the window, and at the same time reads the number of pulses of the forward step signal and records the window position; when it detects that the switch key K3 is closed, the MCU processor controls the motor to rotate in reverse to lower the window, and at the same time reads the number of pulses of the reverse step signal and records the window position.

[0019] S3: The MCU processor reads the sampled voltage value Vx and compares the size of the sampled voltage value Vx with the sampled level VS. When the sampled voltage value Vx is less than the sampled level VS, correspondingly increase the number of pulses of the forward step signal PWM+ and decrease the number of pulses of the reverse step signal PWM-, or increase the number of pulses of the reverse step signal PWM- and decrease the number of pulses of the forward step signal PWM+, and return to step S2; when the sampled voltage value Vx is greater than the sampled level VS, enter step S4.

[0020] S4: Compare the relationship between the number of pulses of the forward stepping signal PWM+ or the number of pulses of the reverse stepping signal PWM- and the standard number of pulses. When the number of pulses of the forward stepping signal PWM+ or the number of pulses of the reverse stepping signal PWM- is greater than the standard number of pulses, the MCU processor stops sending the forward or reverse rotation signal to the motor and returns to step S2; when the number of pulses of the forward stepping signal PWM+ or the number of pulses of the reverse stepping signal PWM- is less than the standard number of pulses, the MCU processor determines that the motor is blocked by an external obstacle and controls the reverse control circuit to work to move the window away from the obstacle and returns to step S2.

[0021] In one embodiment, the device uses ADC sampling or / and PWM recognition sampling.

[0022] Implementing the overload current detection type window anti-pinch device and method of the present invention, the MCU processor obtains the ripple of the motor through a sampling resistor and sends the ripple signal to the MCU processor. During the learning stage, that is, when the motor drives the window to move normally, the MCU processor stores the sampling resistor when the motor moves normally and records the number of pulses Pm sent by the sampling resistor received when the window position moves from the highest end to the lowest end; during the actual operation of the motor, when the sampling voltage value Vx obtained by the MCU processor is greater than the sampling level Vs and the processed number of pulses is less than the number of pulses Pm, the MCU processor determines that the motor is blocked and there is an obstacle at the window. In this case, the MCU processor controls the reverse control circuit to work and moves the window away from the obstacle to avoid pinching passengers or damaging items on the window, so as to improve the safety of window control. This device and method do not involve Hall sensors, and the structure and wiring of the device are simple, with a small volume and low cost. It is easy to control and is conducive to promoting the optimized design of the vehicle system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the module structure of the overload current detection type window anti-pinch device in an embodiment of the present invention;

[0024] Figure 2 is Figure 1 The circuit schematic diagram of the overload current detection type window anti-pinch device in the shown embodiment;

[0025] Figure 3 It is a flowchart of the overload current detection type window anti-pinch method in an embodiment of the present invention;

[0026] Figure 4 It is a flowchart of the training and learning stage of the MCU processor in an embodiment of the present invention;

[0027] Figure 5 It is a flowchart of the working stage of the MCU processor in an embodiment of the present invention. Detailed Embodiments

[0028] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following detailed description of the specific embodiments of the present invention will be given in conjunction with the accompanying drawings. Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0029] Please refer to Figure 1 and Figure 2 The present invention provides an overload current detection type window anti-pinch device 10 with a small volume of the motor 100 and simple vehicle wiring. The device 10 includes a motor 100 electrically connected to the vehicle power supply for driving the window to move; a sampling resistor 200 connected in series with the motor 100 and grounded for detecting the ripple of the motor 100; a filtering circuit 300 for filtering out the interference signals in the signals sent by the sampling resistor 200; an amplifying circuit 400 for amplifying the signals sent by the filtering circuit 300; and a processing circuit 500 for signal processing and feedback control of the motor 100. It can be understood that the sampling resistor 200 is connected in series in the control loop of the motor 100. When the motor 100 is not powered, the sampling resistor 200 terminal is at ground level; when the motor 100 is powered, the sampling resistor 200 terminal receives an AC-DC mixed signal, that is, the ripple signal generated by the motor 100, so as to obtain the source signal. The filtering circuit 300 is used to filter out the interference signals in the ripple signals obtained by the sampling resistor 200 to improve the effectiveness of the signals, avoid the occurrence of window misoperation problems caused by incorrect analysis, and further achieve the purpose of improving the reliable control of the window. The amplifying circuit 400 includes an amplifier for adjusting different amplification factors according to the requirements of the processing circuit 500, ensuring that when the motor 100 starts and stalls due to obstruction, the signal amplitude sent from the sampling resistor 200 to the processing circuit 500 is within the recognition range of the processing circuit 500, thereby improving the sensitivity and reliability of the device 10 for signal processing.

[0030] The processing circuit 500 includes an MCU processor and a control loop for controlling the forward and reverse rotation of the motor 100. The P2.3 pin of the MCU processor is electrically connected to the reference ground through the on-off key K1. The MCU processor is used to send a forward stepping signal or a reverse stepping signal to the motor 100 when the on-off key K1 is closed, read the sampled level Vs sent by the amplification circuit 400, process it, and store it as the number of pulses. The MCU processor is also used to store the number of pulses Pm when the mapped window position moves from the highest end to the lowest end; the control loop includes a forward rotation control loop electrically connected to the P2.1 pin of the MCU processor and a reverse rotation control loop electrically connected to the P2.0 pin of the MCU processor. The P2.2 pin of the MCU processor is connected with an on-off key K2 for triggering the forward rotation control loop to work, and the P2.4 pin of the MCU processor is connected with an on-off key K3 for triggering the reverse rotation control loop to work; when the sampled voltage value Vx obtained by the MCU processor when the on-off key K2 or the on-off key K3 is closed is greater than the sampled level Vs, and the number of pulses processed is less than the number of pulses Pm, the reverse rotation control loop is controlled to work through the P2.0 pin to control the motor 100 to move the window away from the obstacle.

[0031] It should be noted that the device 10 of the present invention includes three sampling methods: ADC sampling, PWM recognition sampling, and joint sampling of ADC and PWM recognition. Correspondingly, for the three sampling methods, the MCU processor is a data acquisition chip or / and a single-chip microcomputer of model ADuC81. When the MCU processor is a data acquisition chip of model ADuC81, the ADC sampling method 20 is adopted. In this case, the filtering circuit 300 is a low-pass filter or a low-pass filtering module composed of multiple resistors and capacitors, such as Figure 2 the low-pass filtering module composed of R2 and C1 shown, which is used to provide an AC-DC mixed signal, that is, to provide an AC-DC sampling signal to the processing circuit 500. When ADC sampling is adopted, the signal amplified by the amplification circuit 400 is directly connected to the ADC detection port of the MCU processor or is processed by a dedicated ADC chip and then transmitted to the MCU processor for processing.

[0032] Further, in an embodiment, the device 10 further includes a clock circuit connected to the MCU processor, and the clock circuit is composed of Figure 2It consists of the crystal oscillator X1 and capacitors C2 - C3 shown, and is used to time the signal reception interval of the MCU processor, so that the MCU processor adjusts the signal output according to the time change. Specifically, when the switch key K2 or the switch key K3 is closed, the MCU processor sends a PWM signal to the motor 100, causing the motor 100 to rotate forward or backward, and records the position of the window through the number of PWM signals, that is, PWM+ or PWM-. For example, when the MCU processor detects the rotation of the motor 100 per unit time, that is, when the window moves, the MCU processor adds 1 to the PWM signal output by the motor 100. When the motor 100 rotates forward to drive the window up, the MCU processor controls PWM+ to increase by 1 and PWM- to decrease by 1 per unit time, and stores the signal; when the motor 100 rotates backward to drive the window down, the MCU processor controls PWM- to increase by 1 and PWM+ to decrease by 1 per unit time, and stores the signal.

[0033] When using PWM recognition sampling, the MCU processor is a single-chip microcomputer, and the filter circuit 300 includes high-pass and low-pass filters for providing an AC signal. Further, when using PWM recognition sampling, the device 10 further includes a comparison circuit 600. The comparison circuit 600 includes a comparator for processing the signal amplified by the amplifier circuit 400 and converting the ripple signal into a PWM signal for the MCU processor to detect. Specifically, after the signal is amplified by the amplifier circuit 400, it is connected to the comparator for comparison, and the corresponding ripple signal is converted into a PWM signal for the MCU processor to detect. The MCU processor judges the position of the window and performs anti-pinch processing by detecting the number and amplitude of the ripple and the number and duty cycle of the PWM.

[0034] In one embodiment, the device 10 further includes a motor 100 drive current detection circuit connected to the reverse control loop. The motor 100 drive current detection circuit is connected to the P1.0 pin of the MCU processor or the 1st pin of the ADC, and includes a resistor R1, a capacitor C1 respectively connected to the reference ground, and a resistor R2 provided between the resistor R1 and the capacitor C1. The resistor R1 is also connected to the forward control loop for obtaining the ripple signal generated by the motor 100.

[0035] Please refer further to Figure 2In one embodiment, the forward control loop is composed of the motor 100, MOS tube T1, MOS tube T2 and MOS tube T4 connected in series, and the reverse control loop is composed of the motor 100, MOS tube T1, MOS tube T2 and MOS tube T3 connected in series. Specifically, when the switch key K2 is closed, the P2.2 pin of the MCU processor receives the action signal and sends a trigger signal to the forward control loop via the P2.1 pin to drive the forward control loop to operate, and make the motor 100 rotate forward to drive the window to rise; when the switch key K3 is closed, the P2.4 pin of the MCU processor receives the action signal and sends a trigger signal to the reverse control loop via the P2.0 pin to drive the reverse control loop to operate, and make the motor 100 rotate in the opposite direction to drive the window to fall.

[0036] It should be noted that before the device 10 is put into use, the MCU processor needs to be trained and learned so that the MCU processor can learn and store the parameters when the window is working normally, so that the MCU processor can analyze and process when the window is blocked. Specifically, when the switch key K1 is closed, the automatic learning mode of the MCU processor is triggered. In this case, the MCU processor will control the motor 100 to rotate forward until the window reaches the highest lifting position, and then control the motor 100 to rotate in the reverse direction until the window reaches the lowest lifting position, and record the number of pulses Pm sent during the movement of the window from the highest position to the lowest position and the sampling level Vs received by the sampling resistor 200 during the process. The sampling level Vs is the voltage value when the window is not blocked and the motor 100 is operating normally. After the device 10 is trained to learn and store standard values such as the number of pulses Pm and the sampling level Vs, it enters the window lifting control mode when the switch key K2 or the switch key K3 is closed. When the window encounters an obstacle during the lifting process, the motor 100 is blocked and overloaded. In this case, the voltage value of the ripple signal detected by the sampling resistor 200, that is, the sampling voltage value Vx rises. The sampling voltage value Vx under this condition is greater than the sampling level Vs when the window is normally lifted and lowered, and when the window clamps an object or encounters an object, the window must not rise to the highest lifting position or fall to the lowest lifting position. Therefore, in this case, the number of PWMs sent by the MCU processor to the motor 100 must be less than the number of pulses Pm. In view of this, the MCU processing can judge whether the window clamps the object by comparing the size of the sampling voltage value Vx and the sampling level Vs and further judging the relationship between the PWM number and the number of pulses Pm, so as to avoid the problem of the window clamping passengers or objects.

[0037] The present invention also discloses an overload current detection type vehicle window anti-pinch method 20, please refer to Figure 1 and Figure 2, the device 10 adopted by this method 20 includes a motor 100 electrically connected to the vehicle power supply for driving the window to move; a sampling resistor 200 connected in series with the motor 100 and grounded for detecting the ripple of the motor 100; a filtering circuit 300 for filtering out the interference signals in the signals sent by the sampling resistor 200; an amplifying circuit 400 for amplifying the signals sent by the filtering circuit 300; and a processing circuit 500 for signal processing and feedback control of the motor 100. The processing circuit 500 includes an MCU processor, a forward rotation control loop electrically connected to the P2.1 pin of the MCU processor, and a reverse rotation control loop electrically connected to the P2.0 pin of the MCU processor. The P2.3 pin of the MCU processor is electrically connected to the reference ground through a switch key K1. The MCU processor is also connected with a switch key K2 for triggering the forward rotation control loop to work and a switch key K3 for triggering the reverse rotation control loop to work. Preferably, the device 10 adopts ADC sampling or / and PWM recognition sampling. Specifically, when referring to the two different sampling methods 20 of the overload current detection type window anti-pinch device 10, the selection of the MCU processor, the type selection of the filtering circuit 300, and the selection of the comparison circuit 600 can be referred to. In other words, the method 20 of the present invention is based on the aforementioned overload current detection type window anti-pinch device 10, and the device 10 adopted by it can be any device in the foregoing embodiments.

[0038] Please refer to Figure 3 , Figure 4 and Figure 5 , the above-mentioned overload current detection type window anti-pinch method 20 includes the following steps:

[0039] S1: When the switch key K1 is closed, the MCU processor sends a forward stepping signal to the motor 100, and reads the sampling level VS during the operation of the motor 100 until the window moves to the positive top end; the MCU processor sends a reverse stepping signal to the motor 100 until the window moves to the negative bottom end, reads the pulse number Pm of the stepping signal and stores it in the EPROOM as the standard pulse number.

[0040] Specifically, the pulse number Pm is the number of pulses sent by the MCU processor to the motor 100 during the process of the window descending from the highest lifting position to the lowest lifting position. Of course, the pulse number Pm is also equal to the number of pulses sent by the MCU processor to the motor 100 during the process of the window ascending from the lowest lifting position to the highest lifting position. The sampling level Vs is the level value of the sampling signal sent by the sampling resistor 200 to the MCU processor under the condition that the window is unobstructed and the motor 100 is working normally, and is used to compare or evaluate the working state of the window.

[0041] When the power switch K1 is closed, the P2.3 pin of the MCU processor receives a signal and enters the automatic learning mode. During this process, the MCU processor first sends a forward stepping signal PWM+ to the motor 100, causing the motor 100 to drive the window to rise. At the same time, it reads the sampled level sent by the sampling resistor 200 during the operation of the motor 100 and uses it as the reference level or standard level for judging the window state until the motor 100 drives the window to the highest lifting position. When the motor 100 drives the window to the highest lifting position, if the motor 100 rotates further forward, due to the effect of the vehicle frame, the resistance on the window increases. Thus, the load of the motor 100 increases, and the sampled voltage value sent by the sampling resistor 200 to the MCU processor rises. In this way, in the automatic learning mode, when the MCU processor detects that the sampled voltage value is greater than the sampled level Vs, it determines that the window has reached the top, and immediately sends a reverse stepping signal PWM- to the motor 100, causing the motor 100 to drive the window to descend until the window descends to the lowest lifting position. During this process, the MCU processor reads and stores the number of PWMs sent to the motor 100 during the process of the window descending from the highest lifting position to the lowest lifting position as the standard pulse number, which is used to judge the position height of the window during the normal operation of the window. It should be noted that the device 10 in this embodiment also has a clock circuit. Thus, since the rotational speed of the motor 100 is constant per unit time, the MCU processor can judge the height of the window according to the window movement time, the number of PWMs sent to the motor 100 during this movement time, and the travel of the window. That is, it judges the lifting height of the window according to the number and positive / negative of the PWMs.

[0042] When the window is at the negative bottom end, that is, when it descends to the lowest lifting position, the reverse stepping signal PWM- sent by the MCU processor to the motor 100 is equal to the standard pulse number, that is, Pm. At this point, the power switch K1 is released, and the training and learning process of the MCU processor is completed.

[0043] S2: The MCU processor detects the opening and closing states of the power switch K2 and the power switch K3. When it detects that the power switch K2 is closed, the MCU processor controls the motor 100 to rotate forward to raise the window, and at the same time reads the number of pulses of the forward stepping signal PWM+ and records the window position; when it detects that the power switch K3 is closed, the MCU processor controls the motor 100 to rotate in reverse to lower the window, and at the same time reads the number of pulses of the reverse stepping signal PWM- and records the window position.

[0044] Specifically, during the use of the car window, when a window lifting or lowering command sent from the outside is received, that is, when the MCU processor detects that either the key switch K2 or the key switch K3 is closed, the MCU processor will control the motor 100 to operate to drive the window to lift or lower. Specifically, when the key switch K2 is closed, the MCU processor sends a forward step signal PWM+ to the motor 100, causing the motor 100 to drive the window to rise. During the rising process of the window, within each unit of time, the forward step signal PWM+ is incremented by 1. The MCU processor can determine the position height of the window based on the value of the forward step signal PWM+. When the key switch K3 is closed, the MCU processor sends a reverse step signal PWM- to the motor 100, causing the motor 100 to drive the window to descend. During the descending process of the window, within each unit of time, the reverse step signal PWM- is incremented by 1. The MCU processor can determine the position height of the window based on the value of the reverse step signal PWM-.

[0045] S3: The MCU processor reads the sampled voltage value Vx and compares the magnitude of the sampled voltage value Vx with the sampled level VS. When the sampled voltage value Vx is less than the sampled level VS, the number of pulses of the forward step signal PWM+ is correspondingly increased and the number of pulses of the reverse step signal PWM- is decreased, or the number of pulses of the reverse step signal PWM- is increased and the number of pulses of the forward step signal PWM+ is decreased, and then return to step S2. When the sampled voltage value Vx is greater than the sampled level VS, proceed to step S4.

[0046] Specifically, during the process of the motor 100 driving the window to lift or lower, the MCU processor reads the sampled voltage value Vx sent by the sampling resistor 200 via the P1.0 pin. This sampled voltage value Vx is the voltage value of the motor 100 during the actual operation of the window. When the sampled voltage value Vx is less than the sampled level VS, the motor 100 is in a normal operating state. In this case, if the key switch K2 is closed, the MCU processor continuously sends the forward step signal PWM+ to the motor 100 to cause the motor 100 to drive the window to rise and increments the forward step signal PWM+ by 1. If the key switch K3 is closed, the MCU processor continuously sends the reverse step signal PWM- to the motor 100 to cause the motor 100 to drive the window to descend and increments the reverse step signal PWM- by 1. Then return to step 2 to re-perform the key switch identification, step signal sending, and voltage value comparison processes.

[0047] S4: Compare the relationship between the number of pulses of the forward stepping signal PWM+ or the number of pulses of the reverse stepping signal PWM- and the standard number of pulses. When the number of pulses of the forward stepping signal PWM+ or the number of pulses of the reverse stepping signal PWM- is greater than the standard number of pulses, the MCU processor stops sending the forward or reverse rotation signal to the motor 100 and returns to step S2; when the number of pulses of the forward stepping signal PWM+ or the number of pulses of the reverse stepping signal PWM- is less than the standard number of pulses, the MCU processor determines that the motor 100 is blocked by an external obstacle and controls the reverse control circuit to work to move the window away from the obstacle and returns to step S2.

[0048] Specifically, when the sampled voltage value Vx is greater than the sampled level VS, that is, when the output voltage of the motor 100 increases, it is determined in this case that the motor 100 is overloaded, that is, the window movement is blocked. If under this condition, the number of pulses of the forward stepping signal PWM+ or the number of pulses of the reverse stepping signal PWM- is less than the standard number of pulses, that is, the window is not fully lowered or does not cover the window of the car door, the situation where the sampled voltage value rises due to the resistance of the top or bottom of the window frame can be excluded, that is, it is determined that the window is due to clamping an obstacle resulting in increased resistance and motor 100 overload problem. Of course, if the sampled voltage value Vx is greater than the sampled level VS and the number of pulses of the forward stepping signal PWM+ or the number of pulses of the reverse stepping signal PWM- is greater than the standard number of pulses, the MCU processor determines that the window is fully lowered or covers the window of the car door and stops sending the stepping signal to the motor 100. In this case, the window moves to the terminal and the MCU processor records the PWM value in the EPROOM.

[0049] In other words, in this embodiment, it is necessary to jointly judge the states of the motor 100 and the window by comparing the sampled voltage value and the number of pulses, so as to improve the sensitivity and reliability of window detection. When the MCU processor determines that the window is blocked, the MCU processor controls the reverse control circuit to work, that is, outputs PWM+ or PWM- stepping signals to the motor 100 to make the window return to its original position to achieve the purpose of preventing pinching. It should be noted that the reverse control circuit in this embodiment is used to change the current working state of the motor 100. For example, when the motor 100 rotates forward and encounters an obstacle, the MCU processor will call the reverse control circuit and control the motor 100 to reverse. When the motor 100 rotates backward and encounters an obstacle, the MCU processor will call the reverse control circuit and control the motor 100 to rotate forward.

[0050] Implementing the overload current detection type window anti-pinch device 10 and method 20 of the present invention, the ripple of the motor 100 is obtained through the sampling resistor 200 and the ripple signal is sent to the MCU processor. During the learning stage of the MCU processor, that is, when the motor 100 drives the window to move normally, the sampling resistor 200 when the motor 100 moves normally is stored and the pulse number Pm sent by the sampling resistor 200 received when the window position moves from the highest end to the lowest end is recorded; during the actual operation of the motor 100, when the sampling voltage value Vx obtained by the MCU processor is greater than the sampling level Vs and the processed pulse number is less than the pulse number Pm, the MCU processor determines that the motor 100 is blocked and there is an obstacle at the window. In this case, the MCU processor controls the reverse control circuit to work and takes the window away from the obstacle to avoid pinching passengers or damaging items with the window, so as to improve the safety of window control. The device 10 and method 20 do not involve Hall sensors, the structure and wiring of the device 10 are simple, the volume is small, the cost is low, it is easy to control, and it is beneficial to promote the optimized design of the vehicle system.

[0051] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0052] The above-described embodiments only express several implementation manners of the present invention, and the description is relatively specific and detailed, but it cannot be understood as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims.

Claims

1. An overload current detection type window anti-pinch device, characterized in that, It includes a motor electrically connected to a vehicle power supply for driving the window to move; a sampling resistor connected in series with the motor and grounded for motor ripple detection; a filtering circuit for filtering out interference signals in the signal sent by the sampling resistor; an amplifying circuit for amplifying the signal sent by the filtering circuit; and a processing circuit for signal processing and feedback control of the motor. The processing circuit includes an MCU processor and a control loop for controlling the forward and reverse rotation of the motor. The P2.3 pin of the MCU processor is electrically connected to the reference ground through a switch key K1. The MCU processor is used to send a forward step signal or a reverse step signal to the motor when the switch key K1 is closed, read the sampled level Vs sent by the amplifying circuit, process it, and store it as the number of pulses. The sampled level Vs is the voltage value when the window is unobstructed and the motor is running normally. The MCU processor is also used to store the number of pulses Pm that map the window position from the highest end to the lowest end. The number of pulses Pm is the number of pulses sent by the MCU processor to the motor during the process of the window descending from the highest lifting position to the lowest lifting position. The control loop includes a forward rotation control loop electrically connected to the P2.1 pin of the MCU processor and a reverse rotation control loop electrically connected to the P2.0 pin of the MCU processor. The P2.2 pin of the MCU processor is connected to a switch key K2 for triggering the forward rotation control loop to work, and the P2.4 pin of the MCU processor is connected to a switch key K3 for triggering the reverse rotation control loop to work. When the sampled voltage value Vx obtained by the MCU processor when the switch key K2 or the switch key K3 is closed is greater than the sampled level Vs, and the number of pulses obtained through processing is less than the number of pulses Pm, the MCU processor controls the reverse rotation control loop to work through the P2.0 pin to control the motor to move the window away from the obstacle. When the switch key K1 is closed, the P2.3 pin of the MCU processor receives a signal and enters the automatic learning mode. The MCU processor sends a forward step signal PWM+ to the motor, causing the motor to drive the window to rise, and reads the sampled level sent by the sampling resistor during the operation of the motor as the reference level or standard level for judging the window state. When the motor drives the window to the highest lifting position, when the MCU processor detects that the sampled voltage value is greater than the sampled level Vs, it determines that the window has reached the top, and sends a reverse step signal PWM- to the motor, causing the motor to drive the window to descend until the window descends to the lowest lifting position. The MCU processor reads and stores the number of PWMs sent to the motor during the process of the window descending from the highest lifting position to the lowest lifting position as the standard number of pulses. When the switch key K2 is closed, the MCU processor sends a positive stepping signal PWM+ to the motor, so that the motor drives the window up; when the switch key K3 is closed, the MCU processor sends a reverse stepping signal PWM- to the motor, so that the motor drives the window down; when the motor rotates forward to drive the window up, the MCU processor controls PWM+ to increase by 1 and PWM- to decrease by 1 per unit time, and stores the signal; when the motor rotates reversely to drive the window down, the MCU processor controls PWM- to increase by 1 and PWM+ to decrease by 1 per unit time, and stores the signal; When the sampling voltage value Vx is less than the sampling level VS, the motor is in a normal working state. If the switch key K2 is closed, the MCU processor continuously sends a positive stepping signal PWM+ to the motor, so that the motor drives the window up, and the positive stepping signal PWM+ is increased by 1; if the switch key K3 is closed, the MCU processor continuously sends a reverse stepping signal PWM- to the motor, so that the motor drives the window down, and the reverse stepping signal PWM- is increased by 1, and the switch key identification, stepping signal sending and voltage value comparison process are repeated; When the sampling voltage value Vx is greater than the sampling level VS, it is judged that the motor is overloaded and the movement of the window is blocked. If the number of pulses of the forward stepping signal PWM+ or the number of pulses of the reverse stepping signal PWM- is less than the standard number of pulses, the window is not completely lowered or does not fully cover the window of the car door, and it is judged that the window is due to the increase of resistance and motor overload caused by the obstruction. If the sampling voltage value Vx is greater than the sampling level VS, and the number of pulses of the forward stepping signal PWM+ or the number of pulses of the reverse stepping signal PWM- is greater than the standard number of pulses, the MCU processor determines that the window is completely lowered or covers the window of the car door, and stops sending stepping signals to the motor. When the MCU processor determines that the window is blocked, the MCU processor controls the reverse control loop to work, that is, outputs a PWM+ or PWM- step signal to the motor to return the window to its original position; Also includes a clock circuit connected to the MCU processor; The forward control loop is composed of a motor, a MOS tube T1, a MOS tube T2 and a MOS tube T4 connected in series, and the reverse control loop is composed of a motor, a MOS tube T1, a MOS tube T2 and a MOS tube T3 connected in series.

2. The device according to claim 1, characterized in that, The MCU processor is a data acquisition chip or / and a single-chip microcomputer of model ADuC81.

3. The device according to claim 2, characterized in that, When the MCU processor is a data acquisition chip of model ADuC81, the filtering circuit is a low-pass filter for providing an AC / DC mixed signal.

4. The device according to claim 2, wherein When the MCU processor is a single chip microcomputer, the filtering circuit includes a high pass filter and a low pass filter for providing an AC signal.

5. The device according to claim 4, characterized in that The device also includes a comparison circuit, which is used to process the signal amplified by the amplifier circuit and convert the ripple signal into a PWM signal for detection by the MCU processor.

6. The device according to claim 2, characterized in that, The device further includes a motor drive current detection circuit connected to the reverse control circuit. The motor drive current detection circuit includes a resistor R1, a capacitor C1 respectively connected to the reference ground, and a resistor R2 disposed between the resistor R1 and the capacitor C1. The resistor R1 is also connected to the forward control circuit.

7. An overcurrent detection type window anti-pinch method, characterized in that, The overload current detection type window anti-pinch device according to claim 1, the device includes a motor electrically connected to the vehicle power supply for driving the window to move; a sampling resistor connected in series with the motor and grounded for motor ripple detection; a filtering circuit for filtering interference signals in the signals sent by the sampling resistor; an amplifying circuit for amplifying the signals sent by the filtering circuit; and a processing circuit for signal processing and feedback control of the motor. The processing circuit includes an MCU processor, a forward control circuit electrically connected to the P2.1 pin of the MCU processor, and a reverse control circuit electrically connected to the P2.0 pin of the MCU processor. The P2.3 pin of the MCU processor is electrically connected to the reference ground through a switch key K1. The MCU processor is further connected with a switch key K2 for triggering the forward control circuit to work and a switch key K3 for triggering the reverse control circuit to work. The method includes the following steps: S1: When the switch key K1 is closed, the MCU processor sends a forward step signal to the motor and reads the sampling level VS during the operation of the motor until the window moves to the positive top end; the MCU processor sends a reverse step signal to the motor until the window moves to the negative bottom end, reads the pulse number Pm of the step signal and stores it in the EPROM as the standard pulse number; the sampling level Vs is the voltage value when the window is unobstructed and the motor runs normally, and the pulse number Pm is the number of pulses sent by the MCU processor to the motor during the process of the window descending from the highest lifting position to the lowest lifting position. S2: The MCU processor detects the opening and closing states of the switch key K2 and the switch key K3. When it detects that the switch key K2 is closed, the MCU processor controls the motor to rotate forward to raise the window, and at the same time reads the pulse number of the forward step signal and records the window position; when it detects that the switch key K3 is closed, the MCU processor controls the motor to rotate in reverse to lower the window, and at the same time reads the pulse number of the reverse step signal and records the window position. S3: The MCU processor reads the sampling voltage value Vx and compares the size of the sampling voltage value Vx with the sampling level VS. When the sampling voltage value Vx is less than the sampling level VS, correspondingly increase the pulse number of the forward step signal PWM+ and decrease the pulse number of the reverse step signal PWM-, or increase the pulse number of the reverse step signal PWM- and decrease the pulse number of the forward step signal PWM+, and return to step S2; when the sampling voltage value Vx is greater than the sampling level VS, enter step S4. S4: Compare the relationship between the number of pulses of the forward stepping signal PWM+ or the number of pulses of the reverse stepping signal PWM- and the standard number of pulses. When the number of pulses of the forward stepping signal PWM+ or the number of pulses of the reverse stepping signal PWM- is greater than the standard number of pulses, the MCU processor stops sending the forward or reverse rotation signal to the motor and returns to step S2; when the number of pulses of the forward stepping signal PWM+ or the number of pulses of the reverse stepping signal PWM- is less than the standard number of pulses, the MCU processor determines that the motor is blocked by an external obstacle and controls the reverse control circuit to work to move the window away from the obstacle and returns to step S2; When the motor rotates forward to drive the window to rise, the MCU processor controls PWM+ to increase by 1 and PWM- to decrease by 1 per unit time and stores the signal; when the motor rotates in reverse to drive the window to descend, the MCU processor controls PWM- to increase by 1 and PWM+ to decrease by 1 per unit time and stores the signal; When the MCU processor determines that the window is blocked, the MCU processor controls the reverse control circuit to work, that is, outputs PWM+ or PWM- stepping signals to the motor to return the window to its original position.

8. The method according to claim 7, wherein The device uses ADC sampling or / and PWM recognition sampling.

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