Wellkeynorm's Electric Tailgate Solution

Wellkeynorm's Electric Tailgate Solution with anti-pinch function

With the development of modern automobile technology, the electronic and intelligentization of automobiles has improved the comfort of automobiles, but at the same time, new standards have been proposed for automobile safety, requiring electric windows to have a certain anti-pinch function.

Electric window anti-pinch can be used for anti-pinch control of electric windows and electric sunroof glass of automobiles and overload protection of lifting motors

Europe and the United States have successively legislated to determine the electric Anti-Pinch Window Lifter (APWL) as the standard configuration of automobiles to improve driving safety and humanization.

Existing APWLs are equipped with a Hall element on the motor of the window lifter to sense whether the motor is subjected to resistance, or other optical sensors are installed.

Anti-pinch window is an important part of car humanization. Its main function is to recognize that the window is in a clamped state after the window is raised and clamped to an obstacle.

And make the window retreat to release the clamping object, prevent the motor from being blocked for a long time and cause burning, and prevent the vehicle occupants from being pinched.

The working principle of the electric window anti-pinch is to install a set of current sensors, and the Hall sensor detects the speed of the motor at all times.

When the electric window is raised, once the speed of the electric motor slows down and the Hall sensor detects a change in the speed, it will report information to the ECU module,

The ECU module sends an instruction to the relay, and the circuit reverses the current, so that the motor stops or reverses (falls), so the window stops moving or falls, so it has a certain anti-pinch function.

Electric window anti-trap is to install a magnetic ring on the motor shaft, and a Hall sensor and ECU module are installed near the magnetic ring. Every time the motor shaft rotates one revolution, the Hall sensor will generate a fixed number of square waves.

When the window encounters an obstacle in the process of rising, the resistance will increase, the motor speed will decrease, and the current will increase, and the decrease of the motor speed will increase the pulse width of the square wave of the Hall signal.

The electronic module can judge whether the window has encountered an obstacle and the magnitude of the clamping force (generally more than 100N is considered to have encountered an obstacle) through the change of the Hall signal pulse width or the motor current.

Calculate the cumulative number of pulses during each rising process to determine whether the electric window is in the anti-pinch area (generally 4~200 mm from the top of the window),

Then it is finally determined whether an anti-pinch effect needs to be produced. If the module determines that anti-trap is required, it will issue a command to make the motor reverse, and the motor will stop after falling for a certain distance (generally about 120 mm)

The window anti-pinch technology is realized through "tactile sense" and "vision".

It will automatically stop the glass lifting work. And "vision" is a more intelligent window anti-pinch, it is actually a set of optical control system,

Monitor whether there are foreign objects within the moving range of the power window, so as to control the movement of the glass without foreign objects touching the glass.

Although high technology is good, security awareness is more important than intelligent configuration. In many models, only the windows of the main driving position have the anti-trap function, the co-pilot and rear windows do not have this function, and the anti-trap function occasionally "failures".

The U.S. Department of Transportation has promulgated MVSS118, and strictly stipulates that cars and minivans enforce power window anti-pinch regulations.

Although there are no relevant laws and regulations in China, it is the development trend of the automobile industry to design a window anti-pinch system without affecting the comfort.