Abstract: A transfer case motor controls the rotation of a cam. The cam actuates various gear states of a transfer case of a four-wheel-drive vehicle. A contact plate rotates with the cam and encodes the position of the cam as a four-bit binary code. The code is such that when the cam travels between any two gear states, one bit of the four-bit code stays constant from the initial gear state until the final gear state is reached. The single bit can thus be observed to determine that the final gear state has been reached. The encoding scheme is also such that the bit which stays constant always assumes the same state.

Abstract: A method is provided for determining the speed and direction of a rotating shaft. A rotor is connected to the shaft. The rotor includes three circumferentially spaced teeth, the first of said teeth having a first center spacing, the second of said teeth having a second center spacing different than the center spacing of the first tooth, and the third of said teeth having a third center spacing different than the center spacing of the second tooth. The centers of each of said teeth is sensed and a signal is produced in response thereto. A first time period to reach the center of the first tooth, a second time period to reach the center of the second tooth and a third time period to reach the center of the third tooth are determined, then the speed and direction of rotation of the shaft are established.

Abstract: An apparatus is provided to determine the speed and direction of a rotating shaft, including a rotor with three circumferentially spaced teeth connected to the shaft. The spacing of the center of the second rotor tooth is wider than the spacing of the center of the first tooth and the spacing of the center of the third tooth is wider than the spacing of the center of the second tooth. A sensor detects the center of each tooth and produces a signal in response thereto. The signal is received by a computer. The computer determines the speed and direction of rotation of the shaft by determining a first time period to reach the center of the first tooth, a second time period to reach the center of the second tooth and a third time period to reach the center of the third tooth.

Abstract: A four-wheel drive vehicle includes a transfer case for controlling the delivery of power between the front and rear wheels of the vehicle. A clutch in the transfer case controls the amount of power delivered to the front and rear wheels in response to a clutch PulseWidth Modulated (PWM) signal which is generated by an electronic powertrain controller. The powertrain controller receives a first signal which is indicative of the rotational speed of a front driveshaft, which transfers motive power from the transfer case to a pair of front wheels, and a second signal which is indicative of the rotational speed of a rear driveshaft, which transfers motive power from the transfer case to a pair of rear wheels.

Abstract: In one embodiment of the present invention, a "one-touch-up" power window system is provided for a motor vehicle. The system includes a controller which controls the power window motor. One function of the controller is to determine whether an obstruction impedes travel of the power window. The controller takes a plurality of samples of the electrical current drawn by the power window motor. If the last sample varies by more than a predetermined amount from any of the past samples taken over a predetermined distance of travel of the window, the controller concludes that an obstruction impedes the travel of the window. The controller then stops or reverses the power window motor to stop or reverse travel of the power window. In this embodiment of the present invention, distance of travel of the window can be inferred from rotations of the power window motor.