A receding horizon yaw moment control law for steer-by-wire and independent drive vehicles

In this paper, a new type of vehicle dynamic control(VDC), called a receding horizon yaw moment con-trol(RHYMC), is proposed for steer-by-wire(SBW) and independent drive vehicles, which can control both the sideslip angle and the yaw rate in a more effective way. To begin with, two control inputs, or the steering wheel angle and the external yaw moment, are obtained by minimizing the cost function over the finite future time horizon, subject to the so called terminal equality constraint. The optimal control input at the starting point of the time horizon is implemented as the current control law. For real-time processing with time-varying speed of a vehicle, the closed form solution of the proposed RHYMC is presented with an exponential function of a Hamiltonian matrix. The stability of the proposed RHYMC is guaranteed by the terminal equality constraint and the monotonic property of the differential Riccati equation. It is shown through simulation and experiment with a small-scale vehicle that the proposed control scheme has better tracking performance for controlling both the sideslip angle and the yaw rate compared with the existing one that does not employ SBW and is based on an infinite horizon optimal control with a single control input.