Principle of Operation
Principle of 0peration
The manual, one-touch and convenience open/close features correspond to the previous models.
The following operations are new to the E65/E66 SHD:
Panic Close
This function is for deliberate closing of the sunroof without anti-trapping protection. It might: be necessary to use this function, for example, in the event of an outside attack or if the roof is jammed.
The control procedure is divided into two phases:
Phase 1:
Holding the switch position "one-touch CLOSE" activates the panic close mode after 0.5s. The sunroof is closed at maximum speed and with modified anti-trapping protection. Releasing the button terminates the panic close, which means that the sunroof is closed with normal anti-trap.
Even in the case of panic closing, the anti-trapping protection remains activated in a modified form. If trapping is detected, the roof only moves back 20 mm. This relieves strain on the mechanical system or gives the attacker the option of backing away.
Phase 2:
The sunroof switch must be released ("Position zero") and immediately pressed again within 1.5 seconds. The sunroof is now closed at maximum power without anti-trapping protection. The actuation time of the SHD motor is a maximum of 15s. In the event of blocking, the SHD motor still receives current until the higher-level motor protection of 15s kicks in or the sunroof lid is moved into the end position.
For safety reasons, it must always be possible to open the sunroof. Releasing the button discontinues the panic close immediately.
If the sunroof is in the lift position, the panic close function cannot be triggered.
As of a vehicle speed of >16 km/h (10mph), panic close does not function.
Anti-trapping Protection
The SHD has anti-trapping protection for all closing functions. In order to detect trapping, hall sensors are integrated into the motor. The sensors provide direct measurement of the closing speed and end positions. They are also used for calculation of the sunroof closing power. The result of the calculations are stored in the control unit as the "characteristic curve".
For each closing operation, the required closing power is determined. The characteristic curve is then calibrated to this value and as closing proceeds, the currently measured values are compared. If the measured force increases to a value above the characteristic curve by more than the triggering threshold, the sunroof is reversed.
In compliance with governmental regulations, the maximum closing power should not exceed 100 N in the range of 25 mm to 4 mm. The mass inertia of the moving parts makes it necessary to reduce the adjustment speed of the roof in this area. This is done by reduction of the voltage applied to the motor. The voltage is adjusted by pulse width modulation (smooth-rundown feature).
Adjustment of Anti-Trapping Protection to the Vehicle Speed
The air flow when driving produces a vacuum at the sunroof. This suction is particularly strong when the roof is closed from the lift position.
The SHD control unit is unable to distinguish this rise in force from trapping of an obstacle. For this reason, the speed signal is included in the anti-trap protection function. The speed signal is provided by the DSC and received by the SHD via the K-CAN-S.
Emergency Mechanical Operation
In the event of an electrical defect, the sunroof can be moved by using the hexagon wrench from the on-board tool kit.