The turning radius of a differentially steered vehicle towing a trailer is controlled when turning so that its turning radius is greater than a minimum allowable turning radius. The turning radius may be autonomously adjusted using a controller to monitor the instantaneous rotational speed differential between the driven wheels and increase or decrease the relative speed between the wheels when the instantaneous rotational speed differential exceeds a threshold rotational speed differential, indicating a turn which is too tight. Alternately, the turning radius may be controlled by the vehicle's operator, who receives a signal from the controller indicating that the vehicle's turning radius is less than the minimum allowable. The operator may then take action to enlarge the turning radius using manual controls.

Provided is a vehicle turning control device which prevents a target yaw rate from being unstable, even if a control gain is changed in accordance with the magnitude of a yaw rate deviation or a road surface frictional coefficient. This vehicle turning control device includes a target yaw rate correction (32). The correction (32) calculates a target yaw rate with respect to the control gain determined based on a vehicle traveling information, using at least one of a plurality of calculated target yaw rates. The control gain is determined such that, as a road surface frictional coefficient decreases or as a yaw rate deviation increases, a yaw response characteristic approaches a basic yaw response characteristic from an initial yaw response characteristic.

Steering a vehicle may include applying a net brake-steering force to a steered wheel sufficient to affect a steering moment upon the steered wheel sufficient to move the steered wheel away from a zero steering angle, and resisting movement of the steered wheel back toward the zero steering angle.

An approach for automated differentially steering either three-wheeled or four-wheeled vehicles in response to input data collected from sensors associated with characteristics of vehicular movement is suitable for vehicles that travel at speeds about or exceeding 15 miles/hour. An automated differential vehicular steering system comprising such an approach includes a drive control computer including a closed loop vehicular motional controller, a plurality of sensing systems comprised of one or more wheel sensors, one or more inertial sensors measuring vehicular movement, and software for modeling a response to outputs from the plurality of sensing systems. The design of the differential vehicular steering system enables improvements in autonomous or unmanned driving, as no user input is needed for steering.

A differentially steered vehicle includes brakes on the powered wheels which are applied via a controller according to different methods to inhibit freewheeling during turns and improve steering responsiveness and stability. The methods include applying braking force to the wheel on the inside of a turn in response to the rate of turn as indicated by the position of the steering control, to the pressure differential across the hydraulic motors driving the wheels and the rotational speed of the wheels.

A controller controls a first drive source and a second drive source based on a rotation speed of a right rear wheel measured by a rotation speed sensor and a rotation speed of a left rear wheel measured by a rotation speed sensor, to thereby independently control a rotation speed of each of a right front wheel and a left front wheel.

The four wheel steering vehicle utilizes a cage system that extends along the longitudinal axis to protect the driver coupled to a center rail chassis. Front and Back independent suspension links extend outward along the lateral axis pivotally connected to the wheel assemblies enabling four wheel independent suspension. A centrally located pivoting shock provides both steering control and suspension attachment for the shock and spring. The vehicle is controlled by the driver using a steering wheel, acceleration pedal, and a brake pedal. The invention provides a feeling of integration with the vehicle as the driver rolls into turns with the vehicle, while minimizing fatigue caused by the continuous resistance to centrifugal cornering forces.

The disclosure provides an electric quad vehicle, a control system, and method of operation. The electric quad vehicle may include a central hub and four legs, each pivotably mounted to the central hub, each leg including an electric motor rotatably coupled to a wheel. Each leg may include a joint allowing the leg to bend to a retracted state with the wheel adjacent the central hub. The electric quad vehicle may include handle bars extending from the central hub including rider controls of acceleration and steering. The electric quad vehicle may include a control system configured to translate rider input to the rider controls into control signals for each of the electric motors.

The present invention relates to a method for controlling a steering system of a vehicle (100). The steering system comprises individually controllable wheel torque actuators (103, 105) on a respective left (104) and right (106) steerable wheel of the vehicle, wherein the wheel torque actuators (103, 105) are controlled during a turning

A drive force control system to increase a yaw rate greater than the yaw rate achieved by rotating a steering wheel to a maximum angle. A target yaw rate is calculated based on a steering angle of the steering wheel. A first predetermined torque and a second predetermined torque are calculated based on a difference between the target yaw rate and an actual yaw rate. When the steering angle of the steering wheel exceeds a first predetermined angle, a first correction torque to correct the first predetermined torque and a second correction torque to correct the second predetermined torque are calculated n accordance with the steering torque.