tailieunhanh - Electric Vehicles Modelling and Simulations Part 6

Tham khảo tài liệu 'electric vehicles modelling and simulations part 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Vehicle Stability Enhancement Control for Electric Vehicle Using Behaviour Model Control 139 Fig. 17. Control structure deduced from the inversion Fig. 18. Inversion of the converter CR a COG b EMR Anti skid strategy by BMC The BMC structure The behaviour model control BMC can be an alternative to other robust control strategies. It is based on a supplementary input of the process to make it follow the model Hautier 1997 Vulturescu 2000 Pierquin 2000 . The process block correspondens to the real plant Fig. 19. It can be characterised by its input vector u and its output vector y. The control block has to define an appropriated control variable u in order to obtain the desired reference vector yref. The model block is a process simulation. This block can be a simplified model of the process. The difference between the process output y and the model output ymod is taken into account by the adaptation block. The output of this block acts directly on the process by a supplementary input Fig. 19. The adaptation mechanism can be a simple gain or a classical controller Vulturescu 2004 . 140 Electric Vehicles - Modelling and Simulations Fig. 19. Example of a BMC structure Application of the BMC control to the traction system The first step to be made is to establish a behaviour model. In this case we choose a mechanical model without slip which will be equivalent to the contact wheel-road in the areas known as pseudo-slip. This model can be considered as an ideal model. However the inertia moments of the elements in rotation and the vehicle mass can be represented by the total inertia moments Jtmod of each shaft motor which is given by _ _ X 2 I Jt m _ J M kred- J 23 The dynamic equation of the model is given by J d mod _ T .mod 1 xn dt .mod mod 24 T rm _ By taking into account the wheel slip the total inertia moments will become Jt _ I M 1 -X kJ 2 25 We now apply the BMC structure for one wheel to solve the skid phenomenon described before. In Fig. 20 we .