Abstract: An automatic wheel alignment system for aligning the wheels of an automotive vehicle includes head units adapted for coupling to the wheels of the automotive vehicle and a hand held module. The wheel units provide angle information related to the alignment of the wheels of the automotive vehicle. The hand held module is coupled to the wheel alignment units and provides information to an operator through a liquid crystal display. The hand held module includes a controller and memory means. A keypad input is provided for receiving an input from the operator. The liquid crystal display includes an liquid crystal display matrix for forming an image. A contrast control means is coupled to the liquid crystal display and provides a contrast signal to the liquid crystal display.

Abstract: A wheel alignment system measures true camber and true pitch. Camber and pitch angles are measured using a head unit coupled to the wheel of the automotive vehicle. True camber and true pitch are calculated based upon measured camber and measured pitch, a camber crosstalk value, and a pitch crosstalk value.

Abstract: An automatic wheel alignment system for aligning the wheels of an automotive vehicle includes head units adapted for coupling to the wheels of the automotive vehicle and a hand held module. The wheel units provide angle information related to the alignment of the wheels of the automotive vehicle. The hand held module is coupled to the wheel alignment units and provides information to an operator through a liquid crystal display. The hand held module includes a controller and memory means. A keypad input is provided for receiving an input from the operator. The liquid crystal display includes an liquid crystal display matrix for forming an image. A contrast control means is coupled to the liquid crystal display and provides a contrast signal to the liquid crystal display.

Abstract: A wheel alignment system uses head units attached to each of the four wheels of an automotive vehicle. Angle measurements are taken using light sources and light sensors. Pitch sensors measure the pitch of the head units with respect to a horizontal plane. The head units are connected to the left and right front wheels of the automotive vehicle. The pitch information is used to compensate for errors in left and right cross-toe measurements between the left and right front wheels of the automotive vehicle.

Abstract: An automotive vehicle wheel alignment system uses a light source and a linear CCD to measure angles. A mask having a slit through which light from the light source is projected onto the surface of the linear CCD is interposed between the light source and the linear CCD. A microprocessor controls the light source and the linear CCD and uses an output from the linear CCD to calculate an angle between the light source and the linear CCD. The microprocessor uses a search algorithm to locate the center of the image projected on the linear CCD. Calibration data for the linear CCD is stored in an EEPROM.