An Overview of the LucasVarity Simulation Laboratory

This paper presents an overview of the LucasVarity Vehicle Simulation Laboratory and its capabilities and benefits to the company's development of brake and brake control systems for the automotive industry. LucasVarity has been using simulation in its product development process since 1991. Two types of simulation are currently used: open loop and closed loop. The Open Loop Simulator (OLS) is a sensor signal design tool and real-time transmitter used primarily to test brake control system algorithms. Closed loop simulation (CLS) includes two levels: non-real-time desktop simulation (CLSDT) or real-time with hardware in the loop simulation (CLSH). Both levels use a vehicle model, designed by LucasVarity engineers, which is currently solved for eighteen degrees of freedom representing three-dimensional vehicle dynamics. Hardware in the loop simulation is performed on the CLSH and may include a brake fixture mounted in a laboratory hydraulic chamber or an entire vehicle. CLSH features a Simulated Drivers Environment including: the Driver Interface Module (DIM), half a vehicle, a semi-immersive virtual reality test track generated by an SGI workstation, and 3-D sound production using a Paradigm Sound Engine. Closed loop simulation is used not only to develop control system algorithms, but all of the company's brake control products at all phases of development. While other driving simulators appear to be used primarily for ergonomics or human factors studies, the CLSH is used to develop brake control systems. This paper further describes the simulation technology and presents some recent simulation applications with the associated benefits to the development process.