CN201517333U - Ripple current detection-based automobile window anti-pinch controller - Google Patents

Abstract

The utility model discloses a car door window prevents pressing from both sides controller based on ripple current detection, including the direct current motor U3 of drive door window, be used for enlarging and take care of and detect direct current motor U3 ripple current and generate drive signal's controller U1, accomplish control algorithm and generate drive signal drive direct current motor U3's full-bridge driver U2, controller U1 including integrated programmable amplifier A1, filter circuit, PWM driver P2, central controller P1, full-bridge driver U2 is provided with direct current motor U3 and just reverses the return circuit, just reverse the return circuit be connected with controller U1 through the pin on the full-bridge driver U2, be provided with the sampling resistance R1 of ripple current between controller U1 and the full-bridge driver U2. The utility model discloses car door window anti-pinch controller external device based on motor ripple current detects is few, simplifies the circuit design, reduces the area of circuit board; low cost and convenient installation and maintenance.

Description

Anti-pinch controller of automobile window based on ripple current detection

technical field

The utility model relates to an anti-pinch controller for automobile windows, in particular to an anti-pinch controller based on ripple current detection.

Background technique

At present, there are mainly two technical methods for realizing the anti-pinch function of automobile anti-pinch electric window, pressure sensing and infrared detection.

The infrared detection method is to use infrared light to detect whether there is foreign matter within the moving range of the electric window, so as to control the movement of the window glass. This method can prevent foreign matter from directly contacting the glass. However, in the special application environment of automobiles, especially in severe weather conditions (heavy rain, dense fog and dust), the performance of infrared light sources will be seriously affected. Due to the harsh reliability requirements of the car, this solution has basically been rejected by most major automotive electronics developers and car manufacturers.

Automobile anti-pinch electric windows based on the pressure sensing method are widely used at present. This scheme often uses Hall elements to monitor the movement (direction and position) of the window. When the moving window is subjected to lateral or positive When stressed, it puts a greater load on the electric motor and subsequently increases the current in the electric motor. When the current increases to a certain level, the algorithm of the program thinks that the glass of the electric window has encountered real resistance during the rising process, and sends an instruction through the microcontroller unit (MCU) to require the motor to stop or reverse (falling) ), thus effectively and reliably realizing the anti-pinch function.

The Hall element is used to provide information such as the number of rotations of the motor, and the algorithm of the program uses this information to calculate whether the window glass has reached the terminal. When the window glass reaches the closing terminal, the MCU will issue an instruction to automatically cut off the current, and the motor will stop running after the current is cut off. The disadvantage of this solution is that the Hall element is added, and a special installation position needs to be designed.

Contents of the invention

In order to solve the problems existing in the use of the prior art, the utility model provides an automobile window anti-pinch control method based on motor ripple current detection, which does not require a Hall element, and does not need a specially designed installation position, which can simplify the controller's operation. Mounted on the car door, providing stable performance.

The technical solution of the utility model to solve the existing problems is: an automobile window anti-pinch controller based on motor ripple current detection, including a DC motor U3 for driving the window, used to amplify and adjust and detect the ripple current of the DC motor U3 And the controller U1 that generates the driving signal, completes the control algorithm and generates the full-bridge driver U2 that drives the DC motor U3 with the driving signal, and the described controller U1 includes an integrated programmable amplifier A1, a filter circuit, a PWM driver P2, and a central controller P1, the full-bridge driver U2 is provided with a DC motor U3 forward and reverse loop, the forward and reverse loop is connected to the controller U1 through the pins on the full-bridge driver U2, and the controller U1 and the full-bridge driver U2 are set Sampling resistor R1 with ripple current.

Compared with the prior art, the utility model has the beneficial effects that a microcontroller and its integrated programmable amplifier, filter circuit, PWM drive circuit, and other analog circuits are used as the controller to run the control program, and the microcontroller is connected To a full-bridge drive chip, through its integrated PWM drive circuit to directly drive the window motor. The ripple current of the window motor is converted into a ripple voltage signal by connecting a resistor in series with the ground pin of the full-bridge driver chip, and then converted into a square wave signal through the programmable amplifier and filter circuit integrated in the microcontroller And over-current signal, providing signals such as speed, position, etc., to judge whether to start the anti-pinch function. The utility model is based on motor ripple current detection, and the automobile window anti-pinch controller has few external devices, simplifies circuit design, reduces the area of circuit boards, has low cost, and is convenient for installation and maintenance.

Description of drawings

Fig. 1 is a block diagram of the utility model;

Fig. 2, Fig. 3 are control flowcharts of the present utility model.

Detailed ways

Referring to Figure 1, this implementation case includes: a DC motor U3 for driving the window, a controller U1 for amplifying and regulating the ripple current of the DC motor U3 and generating a driving signal, and a controller for completing the control algorithm and generating a driving signal to drive the DC motor U3 Full-bridge driver U2, controller U1 includes integrated programmable amplifier A1, filter circuit, PWM driver P2, central controller P1, DC isolation circuit A2, low-pass filter circuit A3, Schmitt comparator A4, comparator B1, Direction selector P3, counter P4.

The connection between the controller U1 and the full-bridge driver U2 is composed of a ripple current sampling resistor R1 connected to the pin of the full-bridge driver U2 and a passive low-pass filter circuit composed of a resistor R2 and a capacitor C1, and is connected to the programmable Amplifier A1 is connected through pin P1.0.

The full bridge driver U2 is used to convert the TTL level control signal into a voltage signal that can directly drive the DC motor U3. The pin is connected with the controller U1. In this implementation case, the forward and reverse circuits of the full-bridge driver U2 are composed of integrated MOS transistors T1, T2, T3, and T4. The IL2 pin is connected, the IH1, IL1 pins are connected to the P1.5 pin of the controller U1, and the IH2, IL2 pins are connected to the P1.4 of the controller U1; the sampling resistor R1 of the ripple current of the DC motor U3 passes through the The source low-pass filter circuit R2 and the capacitor C1 are connected to the pin P1.0 of the programmable amplifier A1 of the controller U1.

When T1 and T4 are turned on, the preset 12V current flows through T1, DC motor U3, and T4 through the DHVS pin, and then flows to the power supply ground through the pin SL2 through the sampling resistor R1. At this time, the DC motor U3 rotates forward ; When T2 and T3 are turned on, 12V flows through T2, DC motor U3, and T3 through the DHVS pin, and then flows to the power supply ground through the pin SL1 and the sampling resistor R1. At this time, the DC motor U3 reverses. When T1, T2, T3, and T4 are all turned off, the DC motor U3 stops running. The ripple current generated by the DC motor U3 during operation generates a ripple voltage signal through the sampling resistor R1, and is input to the P0.1 pin of the controller U1 through the passive low-pass filter circuit R2 and C1. The turn-off and turn-off of the MOS transistors T1, T2, T3, and T4 of the full-bridge driver U2 are controlled by the signals on the IH1, IH2, IL1, and IL2 pins, and these signals are controlled by the P1.4 and P1 of the controller U1. .5 pins are generated.

Below in conjunction with the working principle of this implementation case, further elaborate the utility model.

Referring to Figure 2 and Figure 3, the DC motor U3 will generate a current ripple with periodic characteristics during operation. This current can be detected on the current loop of its full-bridge driver U2, and a ripple voltage signal is generated through the sampling resistor R1 , through the passive low-pass filter circuit R2 and C1, the P0.1 of the controller U1 is input to the programmable amplifier A1 of the controller U1, and the ripple voltage signal input from the P0.1 pin is amplified to a peak value of about 4V , respectively provided to the comparator B1 and the DC isolation circuit A2. Comparator B1 compares the amplified ripple voltage signal with the set reference voltage Vref, generates a digital level 0 or 1, and sends it to the central controller P1 as an overcurrent detection signal; DC isolation circuit A2 converts P0.5 After the DC component of the amplified ripple voltage input by the pin is removed, it is input to the active low-pass filter circuit A3 through the P0.3 pin, and then a square wave signal is generated by the Schmitt comparator A4 and sent to the central processing Device P1, and sent to the period measurement counter P4 through P1 to calculate the current position of the DC motor U3, that is, the position of the window. The central processing unit P1 calculates whether to start the window anti-pinch according to the signal of the period measurement counter P4 of the comparator B1.

The window lift key input is input to the central processing unit P1 through the P1.1 pin, and the central processing unit P1 outputs a 0 or 1 signal to the P1.4 pin and the P1.5 pin through the PWM driver P2 and the direction selector P3 To control the operation of the DC motor U3. When the P1.5 pin outputs 1 and the P1.4 pin outputs 0, the DC motor U3 rotates forward and the window rises; when the P1.5 pin outputs 0 and the P1.4 pin outputs 1, the DC motor U3 reverses When the P1.5 pin outputs 0 and the P1.4 pin outputs 0, the DC motor U3 stops and the window does not move. When the window is raised, if the anti-pinch starts, the controller will control the DC motor U3 to reverse for 3 seconds, and then stop.

When the controller U1 is powered on, it reads the window position data from the EEPROM at the same time, and then reads the key input. If there is a window lift operation, set the corresponding switch signal to drive the MOS tubes T1, T2, T3, and T4 . If an overcurrent signal is detected when the window moves upwards, and the window position is in the anti-pinch starting area, the controller U1 outputs a direction switch signal, and drives the DC motor U3 to reverse Stop after turning for 3 seconds, then the anti-pinch operation is completed. Regardless of the motor's up and down movement, the controller U1 will record how many positions the motor has traveled through the interrupt counting program, and write the position information into the EEPROM when needed.

In each cycle, the voltage will be detected. If the voltage is too low, the data will be written into the EEPROM to avoid data loss caused by power failure.

The utility model mostly uses controller U1, full-bridge driver U2, DC motor U3, programmable amplifier A1, DC isolation circuit A2, active first-order low-pass filter circuit A3, Schmidt comparator A4, comparator B1, central controller P1, PWM driver P2, direction selector P3, counter P4, MOS transistors T1, T2, T3, T4 and other terms, but the possibility of using other terms is not excluded. These terms are used only for the purpose of describing and explaining the essence of the present invention more conveniently; interpreting them as any kind of additional limitation is against the spirit of the present invention.

Claims (4)

1. an automotive window that detects based on ripple current is prevented clip controller, comprise the direct current generator U3 that drives vehicle window, be used for amplifying and nurse one's health and detect direct current generator U3 ripple current and generate the controller U1 that drives signal, finish the full bridge driver U2 of control algolithm and generation drive direct current generator U3, it is characterized in that: described controller U1 comprises integrated programmable amplifier A1, filter circuit, pwm driver P2, central controller P1, full bridge driver U2 is provided with direct current generator U3 rotating loop, described rotating loop is connected with controller U1 by the pin on the full bridge driver U2, is provided with the sampling resistor R1 of ripple current between controller U1 and the full bridge driver U2.

2. as claims 1 described anti-clip controller of automotive window that detects based on ripple current, it is characterized in that: the rotating loop of described full bridge driver U2 is made of integrated metal-oxide-semiconductor T1, T2, T3, T4, T1, T2, T3, T4 are connected with set IH1, IH2, IL1, the IL2 pin of full-bridge type driver U2 respectively, IH1, IL1 pin are connected with the P1.5 pin of controller U1, and IH2, IL2 pin are connected with the P1.4 of controller U1.

3. the anti-clip controller of automotive window that detects based on ripple current as claimed in claim 1, it is characterized in that: the sampling resistor R1 of described direct current generator U3 ripple current is connected with the P1.0 pin of capacitor C 1 with controller U1 programmable amplifier A1 by passive low-pass filter circuit R2.

4. the anti-clip controller of automotive window that detects based on ripple current as claimed in claim 1, it is characterized in that: described controller U1 also comprises dc isolation circuit A2, low-pass filter circuit A3, Schmidt's comparator A4, comparator B1, direction selector P3, counter P4.

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