Odometry
Basic Odometry Concept
Common Wheel Encoders Magnetic Pickup – used in most ABS Hall Effect Optical
Magnetic Pickup ABS
Incremental Optical Encoder w/ Biphase Output
Systematic Errors Unequal wheel diameters. Average of actual wheel diameters differs from nominal wheel diameter. Actual wheelbase differs from nominal wheelbase. Misalignment of wheels. Finite encoder resolution. Finite encoder sampling rate.
Non-Systematic Errors Travel over uneven terrain Travel over unexpected objects Wheel-slippage Change in tire shape over time
Odometry Trailer
References “All About ABS”; Carley, Larry; CarleySofware, Personal web page for Johann Borenstein of Univ of Michigan – many links to papers on odometry including the UMBmark standard.