A soft stop control device for automobile electric windows

[0015] The present invention will be further explained below in conjunction with the drawings:

[0016] figure 1 It is a schematic diagram of the position and connection of the soft stop control device for the power window of the automobile of the present invention. The control device is composed of a door frame 9, a guide rail 8, a window glass 5, a window motor 10 with a Hall sensor, a window switch 2, an electric control unit 1; the window guide rail 8 is fixed on the door frame 9, and the electric control Unit 1 can be fixed on the door frame 9, or integrated with the window motor 10 and then fixed on the guide rail 8. The signal of the window switch 2 is processed by the acquisition circuit inside the control unit 1 and then connected to the input of the single-chip microcomputer. After being processed by the motor drive circuit, the output is connected to the window motor 10 through a wire. The electronic control unit 1 drives the window motor 10 to rotate forward or reverse according to the rising or falling command input by the window switch 2, and the window motor rotates. The force transmitted by the wire bundle can drive the window glass 5 to rise or fall; the Hall pulse signal 11 generated during the rotation of the window motor 10 is processed and connected to the input of the single-chip microcomputer, and the single-chip accurately recognizes the window according to the signal The current position of the glass to achieve the soft stop function; the motor current signal is processed by the processing circuit inside the electronic control unit 1 and connected to the input of the single-chip microcomputer. It is mainly used for the stall control of the window motor when the Hall pulse signal fails. The soft stop function is realized as follows: when the upper soft stop point 4 (or the lower soft stop point 6) is reached during the raising (or lowering) of the window glass 5, the control unit 1 stops driving the window motor 10 , Relying on the inertia of the window glass 5 to make it reach the top dead center 3 (or bottom dead center 7). Therefore, the premise of the reliable operation of the soft stop algorithm is to accurately determine the top dead center 3, the upper soft stop point 4, the bottom dead point 7 and the lower soft stop point 6 of the window. Since the window motor 10 with the Hall sensor is equipped with magnets and Hall elements, a signal will be generated when the magnet passes the Hall element during forward or reverse rotation, which can be processed into the electronic control unit 1. The pulse signal that the single-chip microcomputer can recognize 11. During the initialization process of the algorithm, the movement of the window glass 5 from the bottom dead center 7 to the top dead center 3 is used to record the number of Hall pulses of the entire stroke, and the positions of the top dead center 3 and the bottom dead center 7 of the window are determined accordingly. Remember that the number of Hall pulses generated by the entire travel of the window glass 5 is q, the bottom dead point 7 is defined as the stall position where the window glass 5 runs down to the bottom, and the top dead point 3 is defined as the window glass 5 runs up to For the locked rotor position at the top, the position of the window glass 5 is represented by the number of Hall pulses, the number of Hall pulses corresponding to bottom dead center 7 is 0, and the number of Hall pulses corresponding to top dead center 3 is q. The upper soft stopping point 4 or the lower soft stopping point 6 is determined according to the inertial characteristics of the window lifter. If the number of Hall pulses generated by the inertial operation of the window glass 5 at the top is m, and the number of Hall pulses generated by the inertial operation at the bottom is n, the upper soft stop point 4 is defined as the Hall pulse number is qm. The corresponding position, the lower soft stop point 6 is defined as the position corresponding to the Hall pulse number n.

[0017] figure 2 It is a schematic diagram of the hardware structure of the electronic control unit implementing the soft stop algorithm in the present invention. The control circuit of the electronic control unit includes the following parts: single-chip microcomputer, power processing circuit, window switch signal processing circuit, motor drive circuit, Hall pulse signal processing circuit, and motor current acquisition circuit. The single-chip microcomputer used in the present invention is mainly responsible for collecting relevant input signals, driving the window motor through the output, and executing the soft stop algorithm; the power processing circuit uses the power management chip to convert the input car 12V power into the 5V power that the single-chip microcomputer can use. Power supply for the single-chip microcomputer; the window switch signal processing circuit converts the status signal of the window switch into a single-chip recognizable input signal; the motor drive circuit is composed of a relay drive circuit and a relay. The single-chip microcomputer drives the relay through the relay drive circuit, and then is driven by the relay The window motor rotates; the Hall pulse signal processing circuit uses a comparator to convert the Hall pulse signal into a signal that can be recognized by the input capture interrupt module in the microcontroller; the motor current acquisition circuit is connected in series with the drive circuit of the window motor to 10 milliohms For the sampling resistor, the voltage across the sampling resistor is amplified and processed, and the signal is read by the AD acquisition module of the single-chip microcomputer, so that the current information during the operation of the window motor can be obtained in real time.

[0018] image 3 It is a software flow chart of the soft stop algorithm of the automobile power window according to the present invention. When the system is powered on for the first time, it is initialized first. Initialization is to set the hardware port state in the electronic control unit and the initial value of the global variable in the software algorithm. After initialization, the window switch must be operated to complete the self-window learning process before the soft stop algorithm can work normally and realize the soft stop function. The specific process of self-learning is as follows: first operate the window switch to make the window glass reach the bottom dead center, and continue to operate the window switch at the bottom dead center for 2 seconds to complete the downward blocking, and then operate the window switch to make the car The window glass reaches the top dead center, and the window switch is continuously operated at the top dead center for 2 seconds to complete the upward lock, and there can be no interruption in the entire stroke from the bottom dead center to the top dead center. In this process, the algorithm will record the number of revolutions of the window motor during the entire process from bottom dead center to top dead center of the window glass according to the Hall pulse signal, completing self-learning. In the process of self-learning, the determination of the top dead center and bottom dead center is achieved by the motor blocking. When the motor is locked, the Hall pulse width and current will increase significantly, so it can be judged whether the motor is locked by monitoring the Hall pulse width or current. The counting of the Hall signal and the acquisition of the pulse width are realized by the input capture interrupt module of the microcontroller. After completing the self-learning process, the soft stop algorithm can work normally. The direction of movement of the window glass depends on the state of the window switch. According to the state of the window switch, the control commands can be divided into up, down and stop. When controlling the window glass to rise (or fall), it is necessary to determine whether the window glass is already at the top (or bottom), if it is already at the top (or bottom), the window motor is no longer driven. Judge whether the window glass is already at the top (or bottom) is based on the top (or bottom) mark set in the software. Whenever the window glass runs to the top (or bottom), the software will set the corresponding mark for Avoid driving the window motor in the same direction to cause the motor to block when the window glass has reached the dead center position. When the window glass is rising (or falling), the algorithm will monitor the position of the window glass in real time to determine whether the window glass has reached the upper (or lower) soft stop point. Once it reaches the window glass, it will immediately stop driving the window motor to achieve Soft stop function.

[0019] In addition to the self-learning process after the first power-on, the algorithm's self-learning of the window mechanism characteristics runs through the entire process of the algorithm. Once the self-learning conditions are met, the parameters of the window mechanism will be updated to effectively adapt to the window mechanism Uncertain factors such as aging, wear and tear. The Hall pulse signal is one of the important signals required for the normal operation of the algorithm, and the present invention provides processing measures for the abnormal signal. During the lifting and lowering process of the window glass, the electronic control unit will monitor the Hall pulse signal. If the Hall pulse signal from the window motor is not received for 1.2 seconds, it is considered that the Hall pulse signal is faulty, and the soft The stop function ensures the normal lifting function of the window glass through current blocking, which can effectively prevent the window glass from being unable to rise to the top or fall to the bottom, and improve the reliability of the control device.