Double inverted pendulum is a kind of multi-variable

nonlinear and fast system.When it is controlled by fuzzy controllers

'rule explosion' is caused by many inputs.To solve the problem

fuzzy control strategy is provided based on granular computing.According to the granular theory

error space is divided into different granular elements to constitute coarser granularity and finer granularity.Fuzzy control at the coarser level is adopted to realize robustness

while Proportional-Integral-Derivation(PID) control at the finer level to realize delicate adjustment.The simulations testify that the strategy is effective not only solving the problem of 'rule explosion'

but also achieving the ideal performance of stable state and transient state.