An actuator apparatus includes an actuator rod with an interior cavity and a set of rod holes. Each rod hole extends through the actuator rod to the cavity. The set of rod holes is positioned in a straight line. The apparatus includes a light assembly that is positioned to light the cavity. The apparatus includes an actuator block that includes an opening extending through the actuator block sized to conform to an outer surface of the actuator rod and a set of block holes in the opening. Spacing between the block holes matches spacing between the rod holes. The actuator block includes a light sensor positioned in a block hole to sense light coming through a rod hole aligned with the block hole and a ball bearing for each block hole of the set of block holes without a light sensor and extending partially through the corresponding block hole.

An actuator apparatus includes an actuator rod with an interior cavity and a set of rod holes. Each rod hole extends through the actuator rod to the cavity. The set of rod holes is positioned in a straight line. The apparatus includes a light assembly that is positioned to light the cavity. The apparatus includes an actuator block that includes an opening extending through the actuator block sized to conform to an outer surface of the actuator rod and a set of block holes in the opening. Spacing between the block holes matches spacing between the rod holes. The actuator block includes a light sensor positioned in a block hole to sense light coming through a rod hole aligned with the block hole and a ball bearing for each block hole of the set of block holes without a light sensor and extending partially through the corresponding block hole.

A rail testing system comprises a proximal mobile track system and a distal mobile track system. Each of the proximal mobile track system and the distal mobile track system are movable in a horizontal direction and a vertical direction. A carriage is movably coupled to the proximal mobile track system and the distal mobile track system. The system has a sensor pod comprising a roller search unit. The sensor pod is configured to lock to the carriage for testing of a rail. The system includes a sensor array comprising time of flight sensors. The sensor array is usable to maintain an alignment of the roller search unit with the rail.

A rail testing system comprises a proximal mobile track system and a distal mobile track system. Each of the proximal mobile track system and the distal mobile track system are movable in a horizontal direction and a vertical direction. A carriage is movably coupled to the proximal mobile track system and the distal mobile track system. The system has a sensor pod comprising a roller search unit. The sensor pod is configured to lock to the carriage for testing of a rail. The system includes a sensor array comprising time of flight sensors. The sensor array is usable to maintain an alignment of the roller search unit with the rail.

A method for ensuring the standstill of a rail vehicle, in particular ensuring the standstill of the rail vehicle for safety reasons, uses a vehicle controller of the rail vehicle having an electronic control system in order to implement driving commands and standstill commands in the rail vehicle. In addition, a monitoring instance is used, which is independent of the control system and which detects a movement of the rail vehicle, compares the detected movement with a valid driving command of the vehicle controller and, in the case of a deviation, initiates braking of the rail vehicle independently of the control system in order to bring the rail vehicle to a standstill.

A method for ensuring the standstill of a rail vehicle, in particular ensuring the standstill of the rail vehicle for safety reasons, uses a vehicle controller of the rail vehicle having an electronic control system in order to implement driving commands and standstill commands in the rail vehicle. In addition, a monitoring instance is used, which is independent of the control system and which detects a movement of the rail vehicle, compares the detected movement with a valid driving command of the vehicle controller and, in the case of a deviation, initiates braking of the rail vehicle independently of the control system in order to bring the rail vehicle to a standstill.