A cart power supply device includes a power supply resonance circuit, a notification element, a current detection circuit, and a control circuit. The power supply resonance circuit includes a power supply coil that can be electromagnetically coupled to a power reception coil mounted on a shopping cart or the like. The current detection circuit detects a current flowing through the power supply resonance circuit. The control circuit supplies an alternating current to the power supply resonance circuit at a first level and operates the notification element in a first mode when the detected current is less than a first threshold. The control circuit supplies the alternating current at a second level when the detected current is greater than the first threshold and operates the notification element in a second mode.

A system for monitoring electrical contacts for an overhead trolley line may include a wear sensor arranged such that an electrical contact on a vehicle or work machine for contacting the overhead trolley line is continually or periodically in its line of sight. The wear sensor may be configured to capture spatial data defining the surface profile of the electrical contact. The system may also include a data processing module configured to receive the spatial data and identify a defect in the electrical contact based on the spatial data.

An electric walking assisting vehicle configured such that in accordance with operating amounts acting on an operation part, driving of driving motors is controlled and includes an inclination detector which detects inclination of a vehicle body in a forward-backward direction, and on flat land where inclination is less than a threshold, with an operation origin of the operation part as a center, the driving motors are controlled to generate torque in a forward direction by operation of pushing the operation part forward and to generate torque in a backward direction by operation of pulling the operation part backward, on an uphill road on which the inclination is the threshold value or more, the operation origin is shifted to an pulling operation side, and on a downhill road on which the inclination is the threshold value or more, the operation origin is shifted to a pushing operation side.

A battery-powered dolly in one aspect of the present disclosure includes a handle, a connector, a motor, a wheel, a detector, a rotation information acquirer and a controller. The controller stops supplying an electric power from a battery to the motor based on (i) a battery current value and/or a battery voltage value detected by the detector and (ii) a rotation information acquired by the rotation information acquirer.

An autonomous robot moves materials in a warehouse or other industrial environment. It runs on an electric motor powered by a rechargeable battery. When its battery becomes depleted, it maneuvers to a nearby charger. It guides itself to the charger using visual cues, such as a target on or near the charger, until it establishes a good electrical connection with the charger. Proximity sensors on the charger and/or the autonomous robot determine if the autonomous robot is positioned properly; if so, the charger begins charging the autonomous robot's battery. While charging, the charger monitors the resistance of the electrical connection for open- or short-circuit conditions. It also monitors the status of the proximity sensors. If the charger detects an open-circuit or a short-circuit or that the autonomous robot has moved away from the charger, the charger stops charging.

A drive unit attached to a mobile entity is disclosed. The drive unit includes a motor, a first detector, and a controller. The first detector detects vehicle speed information regarding a vehicle speed of the mobile entity. The controller performs PWM control for the motor. The controller controls a duty cycle of a PWM signal in accordance with the vehicle speed information detected by the first detector.

Wheel assembly (200) a self-propelling trolley (100), comprising a wheel (111,112); an electric motor (151,152) arranged to perform a rocking drive pattern; an electric connector (220), arranged to connect the motor (151,152) to a battery (156); and a mechanical brake (230) activatable so that a rotational movement of the wheel (111,112) is limited, The invention is characterised in that the mechanical brake (230) is arranged so that, in an engaged state, the wheel (111,112) can turn freely in relation to the trolley (100) across a ground distance of between 5 and 20 cm between a first rotary limit position and a second rotary limit position. The movement limitation is provided by several elongated concentric tracks interacting with a pin.

A drive unit attached to a mobile entity is disclosed. The drive unit includes a motor, a first detector, and a controller. The first detector detects vehicle speed information regarding a vehicle speed of the mobile entity. The controller performs PWM control for the motor. The controller controls a duty cycle of a PWM signal in accordance with the vehicle speed information detected by the first detector.

The disclosure relates to an overhead line system for supplying electricity to the drive of one or more construction machines for piece good or bulk material transport, wherein the overhead line comprises at least one pair of lines which extend parallel along the route, carry current with opposing polarity and which can be electrically contacted by corresponding current collectors of the construction machines, characterized in that each line is provided at the end with at least one guide forming a feed channel for receiving the head of the current collector, the feed channel converging in the direction of the associated line.

A vehicle has a current collector for feeding traction energy from a two-pole overhead contact line system, an electric or hybrid electric traction drive, and an electric energy storage device for temporarily storing fed traction energy. A first line branch can connect the traction drive to the current collector. A second line branch, which can connect the traction drive and the energy storage device to the current collector, includes a switched-in, galvanically isolating DC-to-DC converter. Due to a third line branch which can connect the traction drive and the energy storage device to the current collector, and which includes a switched-in, non-galvanically isolating DC-to-DC converter, enables higher charging rates for charging the energy storage device to be transmitted while maintaining the protection system.