scholarly journals Precision Control of Spraying Quantity Based on Linear Active Disturbance Rejection Control Method

Agriculture ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 761
Author(s):  
Xin Ji ◽  
Aichen Wang ◽  
Xinhua Wei

Current methods to control the spraying quantity present several disadvantages, such as poor precision, a long adjustment time, and serious environmental pollution. In this paper, the flow control valve and the linear active disturbance controller (LADRC) were used to control the spraying quantity. Due to the disturbance characteristics in the spraying pipeline during the actual operation, the total disturbance was observed by a linear extended state observer (LESO). A 12 m commercial boom sprayer was used to carry out practical field operation tests after relevant intelligent transformation. The experimental results showed that the LADRC controller adopted in this paper can significantly suppress the disturbance in practical operation under three different operating speeds. Compared with the traditional proportional–integral–differential controller (PID) and an improved PID controller, the response speed of the proposed controller improved by approximately 3~5 s, and the steady-state error accuracy improved by approximately 2~9%.

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shijie Dai ◽  
Yufeng Zhao ◽  
Wenbin Ji ◽  
Jiaheng Mu ◽  
Fengbao Hu

Purpose This paper aims to present a control method to realize the constant force grinding of automobile wheel hub. Design/methodology/approach A constant force control strategy combined by extended state observer (ESO) and backstepping control is proposed. ESO is used to estimate the total disturbance to improve the anti-interference and stability of the system and Backstepping control is used to improve the response speed of the system. Findings The simulation and grinding experimental results show that, compared with the proportional integral differential control and active disturbance rejection control, the designed controller can improve the dynamic response performance and anti-interference ability of the system and can quickly track the expected force and improve the grinding quality of the hub surface. Originality/value The main contribution of this paper lies in the proposed of a new constant force control strategy, which significantly improved the stability and precision of grinding force.


Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 376
Author(s):  
Changhao Sun ◽  
Mengqi Liu ◽  
Chang’an Liu ◽  
Xueling Feng ◽  
Hua Wu

In this paper, a fuzzy adaptive linear active disturbance rejection control (Fuzzy-LADRC) is proposed for strong coupling and nonlinear quadrotor unmanned aerial vehicle (UAV). At present, UAV conveys new opportunities in the industry, such as power line inspection, petroleum conduit patrolling, and defects detection for the wind turbine, because of its advantages in flexibility, high efficiency, and economy. Usually, the scene of the UAV mission has a high risk, and there are internal sensor noise and unknown external disturbance. Thus, the attitude stability and anti-interference ability of UAV are especially essential. To solve the strong coupling problem of UAV, the dynamics model of UAV is established via the Newton-Euler method, and the coupling part of dynamics is modeled as an internal disturbance. According to the function of linear active disturbance rejection control (LADRC) parameters, a Fuzzy-LADRC is proposed to improve the dynamic performance of the system. The proposed control method makes full use of the adaptive ability of the fuzzy controller and the anti-interference ability of LADRC to the nonlinear and strong coupling systems. As we know, this is the first time that Fuzzy-LADRC has been used in UAV control. In the simulation, the performance indicators of four controllers, including Fuzzy-LADRC, LADRC, PID, and Fuzzy-PID are compared and analyzed. The results indicate that the average response speed of Fuzzy-LADRC is 12.65% faster than LADRC, and it is 29.25% faster than PID. The average overshoot of Fuzzy-LADRC is 17% less than LADRC and 77.75% less than PID. The proposed control method can significantly improve the response speed and anti-interference ability of UAV.


1990 ◽  
Vol 112 (2) ◽  
pp. 261-269
Author(s):  
M. J. Lampinen ◽  
H. T. Toivonen ◽  
E. J. Niskanen ◽  
A. Ka¨rkka¨inen

A bypass flow control valve, which is a special kind of cascade control of fluid flow, is described and analyzed in this paper. The main idea of this control method is that the flow can be kept constant at varying pressure differences by using the existing pressure difference over the control valve as an energy source for making adjustments. Some flow-technical limits for the applicability of this method are examined. A theroetical consideration of a servocontrol system, where the desired volume flow is changed by external control, is also presented.


Author(s):  
Dazhou Geng ◽  
Qijuan Chen ◽  
Yang Zheng ◽  
Xuhui Yue ◽  
Donglin Yan

The stabilization of power take-off (PTO) is imperative especially under circumstances of fluctuating input wave energy. In this paper, a flow control valve is introduced to optimize the transient process of the hydraulic PTO, which can contribute to a quicker adjustment and a stronger stability. Under variations of input power and load torque in transient process, an open-loop control method and a closed-loop control method are proposed as the opening law of the above valve, and the hydraulic motor speed, the pressure at the accumulator inlet and the generated power are chosen as indicators to examine the regulation performance. Then, the synergic effect of the flow control valve and the accumulator in the transient process is discussed. The effectiveness of the two presented control methods on the fluctuation suppression is respectively tested and compared in both regular wave and irregular wave situations via simulation. To validate the practical effectiveness of the proposed methods, field experiments are conducted. The results demonstrate that the open-loop control can only improve the damping ability of the hydraulic PTO in the speed raising stage, while the closed-loop control can improve the stability both in the speed raising stage and in the load increasing stage.


2021 ◽  
Vol 11 (6) ◽  
pp. 2685
Author(s):  
Guojin Pei ◽  
Ming Yu ◽  
Yaohui Xu ◽  
Cui Ma ◽  
Houhu Lai ◽  
...  

A compliant constant-force actuator based on the cylinder is an important tool for the contact operation of robots. Due to the nonlinearity and time delay of the pneumatic system, the traditional proportional–integral–derivative (PID) method for constant force control does not work so well. In this paper, an improved PID control method combining a backpropagation (BP) neural network and the Smith predictor is proposed. Through MATLAB simulation and experimental validation, the results show that the proposed method can shorten the maximum overshoot and the adjustment time compared with traditional the PID method.


Author(s):  
Yang Yang ◽  
Yongjian Zhao ◽  
Songyi Zhong ◽  
Yan Peng ◽  
Yi Yang ◽  
...  

2012 ◽  
Vol 472-475 ◽  
pp. 1036-1039
Author(s):  
Chong Yang ◽  
Ke Zhang ◽  
Mei Bai Lu

First a new autopilot design model is presented for the interceptor missile with the blended aerodynamic lift and reaction jet. The reaction jet can improve the response speed, but the structure of control system becomes more complex. Therefore how to design control strategy properly is an urgent problem. Second, considering the discrete property of the lateral pulse jet thrusters and the continuous property of the aerodynamic fins, a kind of ADRC (active disturbance rejection control) autopilot system was designed for the aerodynamic lift/reaction jet missile. Finally, through a testing in the simulation of MATLAB, it is shown that, due to the sufficient utilization of the reaction jet, there is a significant improvement in the fast response and robust performance of the proposed controller. It is applicable to design the autopilot of aerodynamic lift and reaction jet blended missile.


2003 ◽  
Vol 36 (5) ◽  
pp. 861-866 ◽  
Author(s):  
A. Marciniak ◽  
C.D. Bocăială ◽  
R. Louro ◽  
J. Sa da Costa ◽  
J. Korbicz

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Li Ding ◽  
Zhenwei Wang

A robust flight controller based on linear active disturbance rejection control (LADRC) is proposed for stability control of an aerial robot quadrotor under wind gusts. The nonlinear dynamical model of the quadrotor, considering the wind disturbance, is firstly established through Newton-Euler method. Subsequently, a robust LADRC technique is proposed to design the controllers for the inner loop and outer loop of the aircraft. In this control scheme, the linear extended state observer (LESO) serves as a compensator which can effectively reject the wind gusts. Then, a method of parameter tuning is introduced to obtain the optimized control performance. Finally, the effectiveness and advantages of the proposed controller are demonstrated through series of simulation case.


2011 ◽  
Vol 171 (2) ◽  
pp. 283-291 ◽  
Author(s):  
Daisuke Hirooka ◽  
Koichi Suzumori ◽  
Takefumi Kanda

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