Abstract: Systems and techniques for determining a sideslip vector for a vehicle that may have a direction that is different from that of a heading vector for the vehicle. The sideslip vector in a current vehicle state and sideslip vectors in predicted vehicles states may be used to determine paths for a vehicle through an environment and trajectories for controlling the vehicle through the environment. The sideslip vector may be based on a vehicle position that is the center point of the wheelbase of the vehicle and may include lateral velocity, facilitating the control of four-wheel steered vehicle while maintaining the ability to control two-wheel steered vehicles.

Abstract: Systems and techniques for determining deceleration controls to use in a trajectory for use in stopping a vehicle are described. A deceleration determination system may receive a trajectory from a trajectory determination system and determine, based on various deceleration parameters, the appropriate controls to configure in a longitudinal profile of the trajectory and the suitable implementation points for implementing the controls. The deceleration determination system may determine deceleration data for various types of trajectories that a vehicle computing system may select from for operating the vehicle based on current conditions.

Abstract: Techniques for determining that a reference trajectory is free of intersections or potential collisions with objects are discussed herein. Trajectories being generated by a primary computing device of a vehicle can be utilized to select or determine a reference trajectory to be followed by the vehicle. A secondary computing device of the vehicle can identify a current offset from the reference trajectory and utilize the offset with a kinematics model to determine a trajectory that is predicted for the vehicle to drive to return to the reference trajectory. Validation of the reference trajectory may be based on predicted collision data determined using the tracker trajectory. The predicted collision data can be utilized to control the vehicle to follow the reference trajectory or a stop trajectory.