Vibration reduction of flexible fruit picking robot by adaptive input shaping method

An adaptive input shaping algorithm for vibration control of the fruits picking robot was proposed in the situation of flexible load unknown. The angular velocity of manipulator's link was taken advantage to design feed forward impulse preshaping input online. The impulse time and amplitude were calculated through the input and output of the system. Preshaping command would lose its vibration suppressing function when the system frequency changed during manipulator's load varied. Then the vibration of manipulator's tip was suppressed by adaptive shaping input command designed according to preshaping command. Meanwhile, the feasibility of the algorithm was proved through theoretical analysis, and the the robust performance with frequency mismatch was analyzed in detail. Simulations were carried out finally. Results show the algorithm for flexible manipulator can solve load-varying vibration control problem and has qualified tip vibration suppressing and angular input tracking ability.