Alvis Vickers wanted a 3D multi-body simulation model developed for obstacle clearance and handling tests on the MRAV (Multi Role Armoured Vehicle). The model was used to assess both driver accelerations as the vehicle was driven at speed over standard obstacles and the likelihood of grounding whilst crawling over severe obstructions.
The project
At the heart of the simulation is a complex tyre model, developed by Randle, which is designed to cope with slip angles ranging from normal cornering operation through to pure side slip and will even handle contact loss correctly. The model can therefore be used to study limit behaviour and even skid/steer operation. Suspension kinematics are faithfully reproduced as are the highly non-linear gas spring and damper characteristics.
Achievements
The 3D model was used to demonstrate the capability of the vehicle with respect to NATO and ISO handling standards. These tests included transient response (step steer/pseudo random steer input), emergency manoeuvre/lane change and a skid/steer assessment of emergency turning circle. Open loop tests were accomplished by applying predetermined inputs to the steering rack. For the closed loop tests where a maximum speed through a set course was required (i.e. lane change) a path-following driver model has been developed.
- Path following driver model
- Obstacle clearance and skid steer modelling
- Handling simulations to ISO and NATO standards
- Project managed for international consortium