Garbage Grubbing Buckets Control System Based On Flexibility Control

To implement automatic control to the garbage grub system, one should be aware to consider the environment of the workplace, make full use of available equipments, develop optimized hardware platform and control strategy.Due to the high flexibility of the dragline structure of the bridge crane and grub bucket, the motion induced sway of the dragline and the bucket is usually unable to avoid. Often the sway have undesirable consequences. For instance, precise manipulation of payloads would be more difficult, and the actions of the bucket such as grabbing or releasing be influenced. Also collisions might be caused by the sway of buckets. Therefore, anti-sway control was the key and difficult point of the designing work of the controller.Industrial control computer, programmable controller (PLC) and field bus are used as the core of the controller, and photo-electricity encoder as the detecting component, transducer as the driving device. The trolley position is detected by the photo-electricity encoder and gathered by the PLC, and then sent to the control computer. The computer sends control signal to the transducer to drive the crane and the grab bucket.Of the software, input shaping and PD feedback control are used as primary control methods. Input shaping is used to reduce the dragline sway, and PD feedback control is used to obtain accurate positioning of the buckets. A new method named Movement-Relied- Respectively-Processing was developed to combine input shaping and PD feedback control. Compared with OLIS and CLSS, the two control module of MRRP controller don't influent the control effect of each other, so less sway and faster response can be obtained.