Patent Application
20170234051
This disclosure generally relates to a powered window-anti-pinch system, and more particularly relates to applying a slack-removal-signal to a window motor prior to operation of the motor to raise the window. The slack-removal-signal is a predetermined-waveform effective to operate the motor in the first-direction to take-up the slack but not raise the window.
It is known for a window pinch detection system to rely on a change in motor speed to indicate when an object such as a hand or arm is being pinched by a closing window. This method is used reliably when the motor is a rather steady state condition such as after the slack has been taken up by the motor. However, when the window is moved downward, slack or play is typically present in the apparatus that couples the motor to the window that must be taken-up before the window can be raised. As such, the next up motion yields a motor wind up due to slack causing a no load condition for the motor, followed by a loading of the motor by the window lift mechanism (motor gearing lash, cable lash, window holder lash, rotation or window). It has been proposed to disable the pinch detection for some predetermine startup time and/or distance. However, with this disabling of the pinch detection system, finger pinches may occur especially with small gaps such as when the window is nearly closed.
Described herein is a more robust pinch detection system with pinch detection active during first movements of window-up motion that eliminates the windup by implementing a windup removal procedure at end of window down events or immediately prior moving the window upward. The windup distance may be characterized dynamically into a stored table during reversal processes. The windup may be estimated differently between hard stop (bottom of window), and a soft stop (middle window). After a window down event initiated by the operator, the process is applied to the motor to take the mechanical slack.
In accordance with one embodiment, a window-anti-pinch system suitable to operate a powered-window in a vehicle is provided. The system includes a motor and a controller. The motor is coupled to a window by an apparatus. The motor is operable to raise the window when the motor is operated in a first-direction and lower the window when the motor is operated in a second-direction opposite the first-direction. The apparatus is characterized by slack between the motor and the window. The controller is in communication with the motor. The controller is configured to apply a slack-removal-signal to the motor prior to operation of the motor to raise the window when a most-recent-operation of the motor was effective to lower the window. The slack-removal-signal is a predetermined-waveform effective to operate the motor in the first-direction to take-up the slack but not raise the window.
Further features and advantages will appear more clearly on a reading of the following detailed description of the preferred embodiment, which is given by way of non-limiting example only and with reference to the accompanying drawings.
The present invention will now be described, by way of example with reference to the accompanying drawings, in which:
As will be recognized by those in the art, it is typical that the apparatus 18 has, or is characterized by, some amount of slack (i.e.—slop, play, lash, etc.) between the motor 14 and the window 16. That is, in some instances the motor 14, or more specifically the rotor of the motor 14, may move (i.e. rotate) an incremental or small amount without any corresponding movement of the window 16. It will also be recognized that the reverse may be true where the apparatus 18 may allow for some incremental upward or downward movement of the window 16 without any corresponding movement of the window 16. In the former instance, since the motor 14 may move without a corresponding movement of the window 16, the motor 14 is operated in what is commonly called an unloaded condition since the motor 14 is not doing any substantive work other than taking up slack in the apparatus 18 when moving.
When the motor 14 is unloaded (i.e. merely taking up slack) the acceleration/speed of the motor 14 is increased for a given excitation signal when compared to a loaded condition. The sudden deceleration of the motor 14 at the instant that the slack is taken up may be incorrectly interpreted as being due to an object being pitched by the window 16. To overcome this problem, the system 30 (
The system 30 may also include a controller 36 that is effectively in communication with the motor 14 via the motor-driver 32 and/or the motion-sensor 34. The controller 36 may include a processor (not specifically shown) such as a microprocessor or other control circuitry such as analog and/or digital control circuitry including an application specific integrated circuit (ASIC) for processing data as should be evident to those in the art. The controller 36 may include memory (not specifically shown), including non-volatile memory, such as electrically erasable programmable read-only memory (EEPROM) for storing one or more routines, thresholds, and captured data. The one or more routines may be executed by the processor to perform steps for operating the motor 14 based on signals received by the controller 36 from the motor-driver 32 and/or the motion-sensor 34.
In order to remove any slack present in the apparatus 18 prior to raising the window 16 so that the anti-pinch detection function or algorithm can be reliably enabled, the controller 36 is configured (e.g. programmed) to apply a slack-removal-signal 40 (
It is recognized that the battery supply voltage (the supply-voltage 46) in a typical vehicle is generally considered to be unregulated, and may vary from 13V to 16V. As such, it may be advantageous for the controller 36 to be configured to monitor the voltage-value 50 and adjust or determine the duty-cycle 48 used to generate the slack-removal-signal 40. That is, the duty-cycle 48 may be determined based on the voltage-value 50 of the supply-voltage 46 (e.g. B+) used to energize the motor 14.
If the controller 36 is configured to remove the slack immediately prior to operating the motor 14 to raise the window 16, it is preferable to minimize how much time is spent to remove the slack. As such, the slack-removal-signal 40 may be characterized by a signal-interval 52 (T0 in
While not subscribing to any particular theory, it is believed that the anti-pinch algorithm will be most reliable if current in the motor 14 is zero when the motor-operation-signal 44 is applied. As such, the slack-removal-signal 40 may include or may be followed by a pause-interval 54 after the signal-interval 52 and prior to operation of the motor 14 to raise the window 16. During the pause-interval 54 (T1) the motor-voltage 42 applied to the motor 14 is preferably zero so any current present in the motor 14 at the beginning of the pause-interval 54 is allow to decay to approximately zero. Testing suggests that for one motor configuration a suitable value for the pause-interval 54 is sixty milliseconds (60 ms).
It is recognized that it is likely most preferable for the slack-removal-signal 40 to be characterized by or defined by both the duty-cycle 48 and a signal-interval 52 so the slack can be taken-up in the quickest and most reliable manner.
Accordingly, a window-anti-pinch system (the system 30), a controller 36 for the system 30, and a method of operating the system 30 is provided. The system 30 applies the slack-removal signal 40 either immediately following operation of the assembly 10 to lower the window, or immediately prior to operation of the assembly to raise the window, especially when the most recent operation of the assembly 10 was to lower the window 16. That is, the system 30 preferably applies the slack-removal-signal to the motor 14 prior to operation of the motor to raise the window 16 when a most-recent-operation of the motor 14 was effective to lower the window. To minimize the time necessary to remove the slack, the slack-removal-signal is advantageously a predetermined-waveform effective to operate the motor 14 in the first-direction 22 to take-up the slack but not raise the window 16. For example, by applying the slack removal signal 40 to the motor 14, the motor is driven in the first direction 26 in a manner sufficient to take up wide variations in the slack but not sufficient to move the window in the upward direction 20. This is due to the significant difference in torque between what is needed for slack removal versus what is needed for the upward motion 20 which requires higher motor torque. While the configuration of the assembly shown in
While this invention has been described in terms of the preferred embodiments thereof, it is not intended to be so limited, but rather only to the extent set forth in the claims that follow.
