Fault tolerant wheel alignment head and system

A sensing head for use in a wheel alignment system, comprising:

• one or more functional modules, each of which is configured to perform a function usable in obtaining measurements for calculating wheel alignment parameters of a vehicle, wherein the functional modules include at least one of:
• a wireless communication interface module configured to communicate in a wireless manner with a computer system or a companion sensing head attached to the vehicle;
• a spatial relationship sensing module configured to measure a spatial relationship between the sensing head and the companion sensing head;
• an image sensing module configured to producing image data representing an image taken of a target associated with a vehicle wheel;
• and
• an illumination module configured to illuminate the target;
• a data processor configured to calculate the measurements based on data received from the one or more functional modules;
• wherein the one or more functional modules provide operation redundancy by utilizing at least one of:
• providing multiple sets of illumination devices in the illumination module, wherein at least one set is independent from another set and is configured to illuminate the target independently;
• providing multiple paths for communication with the computer system using the wireless communication module, wherein at least one of the paths is different from another path;
• providing multiple sets of illumination devices to the spatial relationship sensing module, wherein at least one set is independent from another set and is configured to independently generate a signal to the companion sensing head;
• and
• providing multiple processing units for implementing the data processor, wherein each processing unit is configured to independently perform the functions of the data processor.