Abstract: 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. Steering angle constraints may be used to limit or prevent saturation of steering by only one set of wheels as well as to reduce sideslip. The steering angle constraints are vehicle independent and applicable across a fleet of different vehicles based on vehicle speed. For instance, the steering angle constraints establish angle limits that dynamically adjust based on vehicle speed to ensure vehicle velocity and acceleration remain within predefined limits as established by autonomous vehicle system design.

Abstract: Techniques for diagnosing and disambiguating a bias in one or more axels of a bidirectional four-wheel drive vehicle. In some examples, the diagnostics system may diagnose and disambiguate the bias in the two axles by collecting data related to the movement of the vehicle while the vehicle traverses a zero curvature path in a forward direction. The diagnostics system may then determine a bias in an axle acting as the rear axle based on the collected data. The bias in the axle acting as the front axle may then be determined based on the collected data and the bias in the rear axle.

Abstract: This application describes systems and techniques for adjusting one or more setting(s) of a vehicle based on detected condition(s) to avoid damage due to contact of the tires with a body, chassis, or other components of the vehicle. In some instances, the vehicle may determine a ride height of the vehicle, determine a limited range of steering angles based at least in part on the ride height, and control operation of the steering system of the vehicle based at least in part on the limited range of steering angles. In some instances, the vehicle may determine a steering angle of the vehicle, determine a limited range of ride heights based at least in part on the steering angle, and control operation of the suspension system of the vehicle based at least in part on the limited range of ride heights.