Four-wheel steering of a vehicle, e.g., in which leading wheels and trailing wheels are steered independently of each other, can provide improved maneuverability and stability. A first vehicle model may be used to determine trajectories for execution by a vehicle equipped with four-wheel steering. A second vehicle model may be used to control the vehicle relative to the determined trajectories. For instance, the second vehicle model can determine leading wheels steering angles for steering leading wheels of the vehicle and trailing wheels steering angles for steering trailing wheels of the vehicle, independently of the leading wheels.

A four-wheel steering control device for independently controlling steering of each of first to fourth wheels disposed in a vehicle. A commanded steering angle acquiring part acquires first to fourth commanded steering angles for first to fourth wheels of a vehicle. A four-wheel turning control rate calculating part determines first to fourth residual angles, by which the first to fourth wheels realize the first to fourth commanded steering angles, from current steering angles and calculate first to fourth turning control rates of the first to fourth wheels on basis of the first to fourth residual angles determined. A control part independently controls steering of each of the first to fourth wheels using the first to fourth turning control rates calculated.

An electric power steering apparatus having independent turning mechanisms for respective four wheels of a vehicle, has a problem in that, when a turning motor fails, a turning mechanism for a corresponding wheel stops functioning, resulting in reduction in the maneuverability and the stability of the vehicle. Turning motors of turning mechanisms independently disposed for respective four wheels of a vehicle, each have a redundant configuration. Specifically, each turning motor is configured as three-phase duplexing motors having two three-phase windings and two inverters for separately driving the three-phase windings.

In one embodiment, a vehicle system includes a chassis and a vehicle bed coupled to the chassis, the vehicle bed comprising an attachment system configured to fasten a detachable mission platform onto the vehicle bed. The vehicle system further includes a plurality of wheels coupled to the chassis and configured to carry the chassis over a ground. The vehicle system additionally includes a control system comprising a processor configured to determine a mission type for the detachable mission platform. The processor is additionally configured to communicate with the detachable mission platform to actuate at least one actuator of the detachable mission platform based on the mission type.

An electrical method for centering telehandler rear wheels preferably includes an electronic control module (ECM), a rear steering cylinder, a pair of rear centering valves, a front steering cylinder, a steer mode valve, at least one steering position sensor, a steering control unit and a mode selection switch. The front and rear steering cylinders are connected to the steer mode valve. The steering control unit directs hydraulic fluid from a hydraulic pump to flow into the front and rear steering cylinders to turn the wheels. A 2W steering mode requires that the rear wheels be straight before going from a 4W steering mode into the 2W steering mode. The ECM monitors a position of the rear wheels through the at least one steering position sensor. If the wheels are not straight, the ECM will open a centering valve to straighten the rear wheels, before going into the 2W steering mode.

A multiple-drive vehicle comprises a first driving position (3) for a first driver provided with first driving means (4), a second driving position (5) for a second driver provided with second driving means (6), a first pair of wheels (9) mechanically connected to the first driving means (4) and a second pair of wheels (10) mechanically connected to the second driving means (6). The first driving means (5) and the second driving means (6) are independent of each other for moving the respective pairs of wheels (9, 10) in an independent manner from each other.

Provided is an electric power steering device including: a front-wheel steering mechanism, which is provided to front wheels of a vehicle, and includes a front-wheel steering motor as a drive source; and a rear-wheel steering mechanism, which is provided to rear wheels of the vehicle, and includes a rear-wheel steering motor as a drive source, wherein the rear-wheel steering motor is configured to be a double-inverter three-phase duplex motor, the double-inverter three-phase duplex motor including two three-phase windings and two inverters each configured to individually drive one of the two three-phase windings. Therefore, the electric power steering device is capable of, even when a failure has occurred in the steering motor of the rear-wheel steering mechanism, maintaining a function of the rear-wheel steering mechanism to secure behavior stability of the vehicle.

Provided is an electric power steering device including: a front-wheel steering mechanism, which is provided to front wheels of a vehicle, and includes a front-wheel steering motor as a drive source; and a rear-wheel steering mechanism, which is provided to rear wheels of the vehicle, and includes a rear-wheel steering motor as a drive source, wherein the rear-wheel steering motor is configured to be a double-inverter three-phase duplex motor, the double-inverter three-phase duplex motor including two three-phase windings and two inverters each configured to individually drive one of the two three-phase windings. Therefore, the electric power steering device is capable of, even when a failure has occurred in the steering motor of the rear-wheel steering mechanism, maintaining a function of the rear-wheel steering mechanism to secure behavior stability of the vehicle.

Methods, apparatus, systems and articles of manufacture are disclosed to perform a tank turn. An example vehicle includes a first wheel and a second wheel, the first wheel located on an end of a first axle, the second wheel located on an end of a second axle, the end of the first axle opposite to the end of the second axle, a first suspension coupled to the first wheel, a second suspension coupled to the second wheel, and a controller to drive the first axle in a first direction, drive the second axle in a second direction, the first direction different from the second direction, and decrease a first suspension load of the first suspension and a second suspension load of the second suspension.

A steering system includes a controller configured to: execute a normal control to control a front-wheel steering device or a rear-wheel steering device based on a target steering angle when a steering-related frequency is determined to fall outside a resonance frequency band; and execute a limiting control when the steering-related frequency is determined to fall within the resonance frequency band. In the limiting control, the controller controls the front-wheel or rear-wheel steering device such that (i) an actual steering angle is constant at a predetermined value, (ii) an absolute value of the actual steering angle gradually decreases from a specific value, (iii) a frequency of the actual steering angle falls outside the resonance frequency band, or (iv) the absolute value of the actual steering angle is less than an absolute value of the latest value of a target extreme value that is an extreme value of the target steering angle.