RXT-G ACP BackTracker Steering system Updated: 2012.03
2001 RXT-G - ACP LongRanger III
The LongRanger III is equipped with AC Propulsion’s BackTracker steering system. This system is designed to keep the trailer directly behind the tow vehicle whether the vehicle is moving forward or backward. The trailer hitch and ball each hold sensors that determine the trailer’s angle to the vehicle. The wheels also hold sensors that determine the trailer’s speed and direction (forward or reverse). Between these systems a PCB controls the directional inputs to a servo motor which adjusts the wheel pitch based on inputs. There is no software involved in the system.
The following pictures show examples of each of the components of the BackTracker steering system.
The PCB and various pots to refine and adjust the steering system.
The htich ball. Note the machining to accomidate the ball sensor four (4) pictures below.
Note the Blue cover on the hitch assembly. It houses the corresponding sensor that reads the hitch angle from the ball's angle.
Here are the wheel sensors. One reports speed and the other reports direction back to the PCB.
The following set of pictures show the rack and pinion (worm gear) assembly. This assembly also holds the servo motor and gears.
The servo motor has a white support rim where a cap mounts to ensure water tight operations.
This is the interior of the servo motor gear housing.
The internals of the rack and worm gear / ball bearing system are shown here. This design takes the lateral pressure off the servo motor and allows smooth controled operations.
The next two pictures show the BackTracker steering in operation. Note as the vehicle moves forward and the front wheels of the vehicle turn to the right, the BackTracker steering is compensating by steering the trailer to the left; thus maintaining the trailer's position directly behind the vehicle.
Note the two (2) lag bolts and lock nuts under the 2x2" reciever. We added these to eliminate all motion from the hitch coupling system. This ensures that the hitch & ball remain rigid to the vehicle's frame at all times. With this modification the trailer is perfectly quiet behind the vehicle and the steering geometry reads the precise angle of the trailer.
A short video from AC Propulsion showing their RXT-G backing up on the tzero. Note how the BackTacker steering system automatically keeps the trailer directly behind the vehicle.