System and method for determining angular displacement, velocity and acceleration of a rotating member mounted to a platform

A system for determining angular displacement, velocity and acceleration of a wheel hub bearing assembly mounted to a vehicle, the system comprising:

• at least one digital storage disk having data stored concentrically thereon, the data being provided in the form of pits and lands, the disk mounted on an outer periphery of the wheel hub, the disk and wheel hub having the same axis of rotation,
• at least one laser transmitter for emitting a laser beam directed towards the disk,
• at least one laser receiver for receiving a reflected portion of the emitted laser beam,
• at least one processor, and
• at least one memory storing software thereon for determining the angular displacement, velocity and acceleration of the rotating member, the software comprising instructions being executable by the at least one processor to cause the system for determining the angular displacement, velocity and acceleration of the wheel hub to:
• identify the number of bits per circumference of the disk counted during an initial test run to establish a calibrated bit count value, the calibrated bit count value being recorded into the memory,
• determine the number of bits per circumference of the disk counted during a verification cycle, the verification cycle bit count value being recorded into memory,
• determine a ratio between the number of bits counted during the calibration cycle against the number of bits counted during the verification cycle, and
• calculate an angular displacement of the wheel hub based on the ratio determined between the calibrated cycle and verification cycle,
• calculate the angular displacement of the wheel hub into angular velocity by taking the ratio of change in angular displacement with respect to time, and
• calculate the angular displacement of the wheel hub into angular acceleration by taking the ratio of change in angular velocity with respect to time.

A method for determining angular displacement, velocity and acceleration of a rotating member, the method comprising:

• providing at least one digital storage disk having data stored concentrically thereon, the data being provided in the form of pits and lands, the disk mounted on an outer periphery of the rotating member, the disk and rotating member having the same axis of rotation, at least one laser transmitter for emitting a laser beam directed towards the disk, at least one laser receiver for receiving a reflected portion of the emitted laser beam, at least one processor, and at least one memory storing software thereon for determining the angular displacement, velocity and acceleration of the rotating member,
• the software comprising instructions being executable by the at least one processor to cause the system for determining the angular displacement and velocity of the rotating member to carry out the following steps:
• identifying the number of bits per circumference of the disk counted during an initial test run to establish a calibrated bit count value, the calibrated bit count value being recorded into the memory,
• determining the number of bits per circumference of the disk counted during an verification cycle, the verification cycle bit count value being recorded into memory,
• determining a ratio between the number of bits counted during the calibration cycle against the number of bits counted during the verification cycle,
• calculating an angular displacement of the rotating member based on the ratio determined between the calibrated cycle and verification cycle,
• calculating the angular velocity by taking the ratio of change in angular displacement with respect to time, and
• calculating the acceleration by taking the ratio of change in angular velocity with respect to time.