Combination of input shaping and radial spring-damper to reduce tridirectional vibration of crane payload

The input shaping technique alters the human-operator commands to reduce the payload oscillation. A single radial spring-damper can simultaneously produce three dampings to suppress the tridirectional vibration of a crane payload. Combination of input shaping and radial spring-damper can be a sensorless approach to reduce the vibration induced by both operator commands and external disturbances. A numerical simulation of a boom crane is carried out to clarify the effectiveness of each component in the combination. An experiment of a laboratory boom crane is presented to show the effect of radial spring-damper.