In an apparatus for controlling operation of an automatic door with minimum error in a detected door position, a motion sensor is positioned relative to a movable driving member coupled to the door. Pulses having a pulse repetition rate are created in direct proportion to a velocity of movement of the driving member. The pulses are counted and current position of the door determined. Any error arising from a loss or slip in an intermediate transmission mechanism which couples a motor with the final driving member is substantially eliminated. A pair of motion sensing elements as opto-electronic couplers may be provided for sensing a phase relationship between the sensing elements defining a direction of door movement. A pulse interval monitor adapted to generate a signal indicative of a long lapse of time between adjacent pulses from the sensing element may be provided. A sequence control circuit responsive to this generated signal generates a stop command for the motor.

A system is disclosed for controlling a motor which drives an operating mechanism for moving a door, such as an overhead garage door, in either direction between a closed position and an open position in response to actuation of a start switch. The control system includes an encoder including a rotatable disc driven by the motor and control circuitry including an encoder pulse verification circuit associated with the encoder for detecting the direction of door movement as well as increments of travel by the door when the door is moved by the motor under control of a motor command circuit in response to actuation of the start switch. The start switch and a start circuit cooperate with the motor command circuit for energizing the motor to move the door in one direction, for de-energizing the motor to stop the door at any position, and for re-energizing the motor to reverse the door in response to repeated actuation of the start switch. An up/down counter circuit is responsive to the direction as well as the increments of travel by the door for containing a count representative of the actual position of the door. A programming circuit is included for setting an up limit setpoint which is stored in a latch circuit. A decoder circuit cooperates with the motor command circuit, the up/down counter circuit, the latch circuit, and a comparator circuit for de-energizing the motor when the door reaches the up limit setpoint as the door is opened. The decoder circuit cooperates with the motor command circuit and the up/down counter circuit for de-energizing the motor when the door reaches the threshold as the door is closed. An obstruction detector circuit is responsive to rate of movement of the door for sensing an obstruction. The obstruction detector circuit cooperates with the motor command circuit for de-energizing the motor if an obstruction is sensed as the door is opened and cooperates with the motor command circuit, the up/down counter circuit, and the decoder circuit for reversing the motor if an obstruction is sensed as the door is closed unless the door is a predetermined distance or less above the threshold whereupon reversal of the motor is inhibited and the motor is merely de-energized. A reset circuit is included for resetting the control circuitry so that the initial actuation of the start switch will cause the door to be opened. Other features are also disclosed.

A method and apparatus for operating and monitoring the opening and closing cycle of electrically operated units such as electric windows and electric slide roofs which both eliminates the danger of body parts getting caught in the window and permits a complete opening and closing of the window automatically. In accordance with the invention, the speed of the drive motor is measured, directly or indirectly, and the first obtained measured value is compared with all following measured values. More particularly, this first measured value is used to detect momentary electrical and mechanical factors which change over the entire time of operation of the window, such as self-heating of the drive motor, the voltage charge of the battery, and the state and condition of the window. The processing or comparing of the measured values is carried out by a microcomputer. The actual measuring of the speed is by means of a sensor. The changes furnished by those sensors are utilized to determine the position of the window. This recognition of the position makes it possible in case of danger, to safely turn off the drive motor and possibly to open the window again. Further still, in a normal case, the window may be closed completely.

An automatic control system for controlling the operation of a sliding door system employs an electric motor for driving the sliding door system. An encoder is mounted to the shaft of the motor for generating signals which are decoded to detect the operational position of the sliding door system. A clock paced sequential logic circuit produces speed and directions signals in accordance with the detected operational position to control the speed and direction of the electric motor. Means are provided for recording the last stop position and slowing the sliding door system prior to reaching the last stop position. Safety means are provided to de-energize the motor in the event of malfunction of the motor speed control. The system also includes a reduced opening stop feature and a means for automatically establishing a sliding door reference position.

A windshield wiper control circuit is described wherein the time at which the wiper motor is deenergized after an operating switch has been switched off is determined by the wiper speed. The parking position of the wiper is thereby independent of the condition of the windshield.