A PI control strategy based on fuzzy set-point weighting following was proposed for the active damping control of a hydraulic crane boom system （HCBS）. Two valve-controlled PI controllers, which include a proportion...A PI control strategy based on fuzzy set-point weighting following was proposed for the active damping control of a hydraulic crane boom system （HCBS）. Two valve-controlled PI controllers, which include a proportional feedforward controller based on fuzzy set-point weighting following and a limited semi-integrator（LSI）, are designed respectively. LSI is used to limit output signal and to prevent wind up at the low frequency of the spectrum. By using a range camera and an electronic feedback control, the tip damping on the HCBS can be adjusted artificially. A collaborative control simulation technique of HOPSAN and MATLAB/SIMULINK is applied to the controller design. Simulation results show that the proposed PI control system has less overshoot as well as faster response. The tip damping on the HCBS during operation is improved.展开更多
Pesticide efficacy tests are typically conducted in experimental plots which involve applying multiple chemical treatments at different application rates and timings. Utilizing a single boom pesticide applicator requi...Pesticide efficacy tests are typically conducted in experimental plots which involve applying multiple chemical treatments at different application rates and timings. Utilizing a single boom pesticide applicator requires navigating to individual plots, applying a pesticide assigned to those plots and when all replications are completed, cleaning the equipment and reloading the next pesticide treatment into the tank. It usually takes several hours to accomplish this task, especially when the left hand side of a plot requires a different pesticide treatment than the right hand side. In order to facilitate application of pesticide treatments in experimental plots, two map-based controller systems were developed to drive multi-channel pesticide applicators. The Clemson “Multi-Channel Chemical Controllers” consist of solid-state relays controlled by custom software, solenoid valves, and GPS receivers. The first system can control up to 24 individual booms which could independently apply up to 24 different chemical treatments in each field plot area. The second system is the Clemson “Intelligent Farm Controller” (iFc), which could be connected to a variety of devices, such as spray and motor actuators. For this study, the controller was designed to handle four output pins to control four relays;however, it could easily be expanded to control more relays, if needed. On average, these systems reduced application times in test fields from six hours to 20 minutes, compared to single-boom applicators (p = 0.001), thereby reducing the time interval between treatment applications and significantly reducing the potential effect of adverse weather.展开更多
基金This work was supported by the Natural Science Foundation of Hunan Province(No.04JJ6033) and Scientific Research Fund of Hunan ProvincialEducation Department(No. 03C066).
文摘A PI control strategy based on fuzzy set-point weighting following was proposed for the active damping control of a hydraulic crane boom system （HCBS）. Two valve-controlled PI controllers, which include a proportional feedforward controller based on fuzzy set-point weighting following and a limited semi-integrator（LSI）, are designed respectively. LSI is used to limit output signal and to prevent wind up at the low frequency of the spectrum. By using a range camera and an electronic feedback control, the tip damping on the HCBS can be adjusted artificially. A collaborative control simulation technique of HOPSAN and MATLAB/SIMULINK is applied to the controller design. Simulation results show that the proposed PI control system has less overshoot as well as faster response. The tip damping on the HCBS during operation is improved.
文摘Pesticide efficacy tests are typically conducted in experimental plots which involve applying multiple chemical treatments at different application rates and timings. Utilizing a single boom pesticide applicator requires navigating to individual plots, applying a pesticide assigned to those plots and when all replications are completed, cleaning the equipment and reloading the next pesticide treatment into the tank. It usually takes several hours to accomplish this task, especially when the left hand side of a plot requires a different pesticide treatment than the right hand side. In order to facilitate application of pesticide treatments in experimental plots, two map-based controller systems were developed to drive multi-channel pesticide applicators. The Clemson “Multi-Channel Chemical Controllers” consist of solid-state relays controlled by custom software, solenoid valves, and GPS receivers. The first system can control up to 24 individual booms which could independently apply up to 24 different chemical treatments in each field plot area. The second system is the Clemson “Intelligent Farm Controller” (iFc), which could be connected to a variety of devices, such as spray and motor actuators. For this study, the controller was designed to handle four output pins to control four relays;however, it could easily be expanded to control more relays, if needed. On average, these systems reduced application times in test fields from six hours to 20 minutes, compared to single-boom applicators (p = 0.001), thereby reducing the time interval between treatment applications and significantly reducing the potential effect of adverse weather.
