Monitoring vehicle restraints over a continuous range of positions

A method of using a barrier to selectively block and release a vehicle at a dock, the barrier being selectively movable to a fully extended position, a fully retracted position, and a plurality of intermediate positions between the fully extended position and the fully retracted position, the barrier being under command of a controller that uses a sensor to monitor a position status of the barrier, the method comprising:

• commanding the barrier to retract through a plurality of intermediate positions;
• monitoring the position status of the barrier, via the sensor;
• and
• providing a bump-back signal in response to
• the barrier failing to move to the fully retracted position, the bump-back signal to provide notification to a driver of a vehicle to move the vehicle away from the barrier.

A tangible computer-readable medium comprising instructions that, when executed, cause a machine to:

• move a barrier via a vehicle restraint drive unit relative to a main body proximate a dock between a fully extended position to block a vehicle, a fully retracted position to release the vehicle, and a plurality of intermediate positions between the fully extended position and the fully retracted position, the barrier to provide a more prominent obstruction to the vehicle when the barrier is in the fully extended position than when the barrier is in the fully retracted position;
• monitor a status of the barrier as the barrier moves through the plurality of intermediate positions;
• compare the status to a reference value;
• determine that an event has occurred based on the comparison of the status and the reference value;
• provide an output in response to determining that the event has occurred;
• command the barrier to retract through a plurality of intermediate positions;
• and
• provide a bump-back signal in response to the barrier failing to move to the fully retracted position, the bump-back signal to provide notification to a driver of the vehicle to move the vehicle toward a wall of a loading dock when the barrier is engaged with the vehicle.