Safety Window ECU
MULTIPLEX COMMUNICATIONSAFETY WINDOW ECU
DESCRIPTION
Safety window ECU is installed on each door and receives the power window control signal from the driver side door module via LIN communication with the driver side door module and controls the power window up/down motor operation output.
Besides the safety window ECU will detect motor rotation pulse signal via hole IC installed on each motor. The pulse signal is used to detect the stick by foreign material during the power widow up operation or the manual up operation. Upon detection safety window, ECU reverses the motor operation output (150 mm down). It is called the safety window control.
Communication Block Diagram:
BLOCK DIAGRAM
GENERAL OPERATION
1. Control the power window motor by means of LIN communication between Safety power window ECU and Power Window Main / Assist, or direct Up/Down switching.
2. Software recognizes the error on the system. For example, Hall IC error (impossible to determine the window position), Wrong normalization information or EEPROM (hardware error) error. ECU will get an execution of software reset. Exception position data, RAM data will be preserved.
NOTE: If software system reset generates, All kinds of window movement (Manual. Auto Up/Down) become terminated immediately except the reverse movement by safety function.
3. Software provides an algorithm in order to present the motor from thermal overheating under the specified conditions like EEPROM Data valid. After power on reset, the software thermal counter takes an initial value. In case of motor running, software increases the thermal counter by using the motor heating characteristic, otherwise the thermal counter decrease by using the motor cooling characteristic.
There are 2 thermal protection limits. If the software thermal counter passes the first limit and actual movement is finished, motor movement is disabled until software thermal counter decreases to the release limit temperature value. If the software thermal counter passes the second limit (while motor running) movement will stop at once until release temperature value is reached (reversing will not be interrupted by software thermal protection).
4. After power on reset or error detection, the motor has to be normalized at the top travel position of window.
How to initialize:
Use Up function to move the window into the Fully closed position. As the window reaches the Fully closed position, press the power window switch for 200 ms. If block detection recognizes the top travel position of window, a system state changes to normalized.
After system is normalized, move the window 5 times upwards and downwards completely in order to adapt the system on door characteristics.
5. As the safety function is active, ECU will stop all sort of auto-up function at once and the motor moves to the down direction 150 mm from the point where the safety function becomes activated. As motor reaches the 150 mm down position from or the bottom travel position of window, the motor stops. Reversing can't be interrupted by any other function, except hardware reset. If the system generates a software system reset (e.g. detection of failed hall sensor signals) the reversing time will be limited to (5 ± 0.4) seconds.