scholarly journals Dual-Arm Coordinated Control Strategy Based on Modified Sliding Mode Impedance Controller

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4653
Author(s):  
Xuefei Liu ◽  
Xiangrong Xu ◽  
Zuojun Zhu ◽  
Yanglin Jiang
Keyword(s):  
Control Strategy ◽  
Control Algorithm ◽  
Sliding Mode ◽  
Impedance Control ◽  
Coordinated Control ◽  
Internal Force ◽  
Target Object ◽  
Stability And Convergence ◽  
Object A ◽  
Dual Arm

To meet the high-accuracy position/force control requirements of dual-arm robots for handling a target object, a control algorithm for dual-arm robots based on the modified sliding mode impedance controller MSMIC(tanh) is proposed. First, the combinative kinematics equation of the dual-arm robots and the unified dynamics model combining the manipulated object is established. Second, according to the impedance control motion model for the object, the desired joint angular accelerations of the manipulators are obtained, and the sliding mode controller based on the hyperbolic tangent function as the switch function is introduced to design the coordinated control strategy for dual-arm robots. The stability and convergence of the designed controller are proved according to the Lyapunov function theory. Finally, the operation tasks of the coordinated transport the target object for dual-arm robots are carried out in the simulated experiment environment. Simulation results show that the proposed control scheme can stably output the required internal force and achieve a high-precision trajectory tracking effect while reducing the periodic torque and joint chattering amplitude generated in the conventional sliding mode control algorithm.

Speed regulation control of tractors’ new dual-flow transmission system based on slip rate resistance classification

2021 ◽  
pp. 095440702110105
Author(s):  
Guang Xia ◽  
Yan Xia ◽  
Xiwen Tang ◽  
Linfeng Zhao ◽  
Baoqun Sun
Keyword(s):  
Control Strategy ◽  
Control Algorithm ◽  
Production Efficiency ◽  
Sliding Mode ◽  
Slip Rate ◽  
Speed Control ◽  
Working Environment ◽  
Vehicle Speed ◽  
Speed Change ◽  
Simulation Results

Fluctuations in operation resistance during the operating process lead to reduced efficiency in tractor production. To address this problem, the project team independently developed and designed a new type of hydraulic mechanical continuously variable transmission (HMCVT). Based on introducing the mechanical structure and transmission principle of the HMCVT system, the priority of slip rate control and vehicle speed control is determined by classifying the slip rate. In the process of vehicle speed control, the driving mode of HMCVT system suitable for the current resistance state is determined by classifying the operation resistance. The speed change rule under HMT and HST modes is formulated with the goal of the highest production efficiency, and the displacement ratio adjustment surfaces under HMT and HST modes are determined. A sliding mode control algorithm based on feedforward compensation is proposed to address the problem that the oil pressure fluctuation has influences on the adjustment accuracy of hydraulic pump displacement. The simulation results of Simulink show that this algorithm can not only accurately follow the expected signal changes, but has better tracking stability than traditional PID control algorithm. The HMCVT system and speed control strategy models were built, and simulation results show that the speed control strategy can restrict the slip rate of driving wheels within the allowable range when load or road conditions change. When the tractor speed is lower than the lower limit of the high-efficiency speed range, the speed change law formulated in this paper can improve the tractor speed faster than the traditional rule, and effectively ensure the production efficiency. The research results are of great significance for improving tractor’s adaptability to complex and changeable working environment and promoting agricultural production efficiency.

scholarly journals Research and Ground Verification of the Force Compliance Control Method for Space Station Manipulator

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Bingshan Hu ◽  
Huanlong Chen ◽  
Liangliang Han ◽  
Hongliu Yu
Keyword(s):  
Real Time ◽  
Contact Force ◽  
Control Algorithm ◽  
Control Method ◽  
Impedance Control ◽  
Space Station ◽  
Gravity Compensation ◽  
Compliance Control ◽  
Experiment Platform ◽  
Dual Arm

The space station manipulator does lots of tasks with contact force/torque on orbit. To ensure the safety of the space station and the manipulator, the contact force/torque of manipulator must be controlled. Based on analyzing typical tasks’ working flows and force control requirements, such as ORU (orbit replacement unit) changeout and dual arm collaborative payload transport, an impedance control method based on wrist 6 axis force/torque feedback is designed. For engineering implementation of the impedance control algorithm, the discretization method and impedance control parameters selection principle are also studied. To verify the compliance control algorithm, a ground experiment platform adopting industrial manipulators is developed. In order to eliminate the influence of gravity, a real-time gravity compensation algorithm is proposed. Then, the correctness of real-time gravity compensation and force compliance control algorithm is verified on the experiment platform. Finally, the ORU replacement and dual arm collaborative payload transport experiments are done. Experimental results show that the force compliance control method proposed in this paper can control the contact force and torque at the end of the manipulator when executing typical tasks.

scholarly journals Virtual Oscillator Control of Multiple Solar PV Inverters for Microgrid Applications

2020 ◽  
Vol 24 (5) ◽  
pp. 173-183
Author(s):  
Han Min Htut ◽  
Wijarn Wangdee
Keyword(s):  
Control Strategy ◽  
Control Algorithm ◽  
Sliding Mode ◽  
Power Sharing ◽  
Solar Pv ◽  
Maximum Power Point ◽  
Load Power ◽  
Control Scheme ◽  
Power Point ◽  
Pv Generation

This paper proposes the inverter control strategy for multiple solar PV generation sources based on the two-stage converters with a combination of the modified virtual oscillator control (VOC) and the cascaded sliding mode control (SMC). With this proposed control strategy, the load power-sharing in proportion to the inverter rating is guaranteed when the solar PV output satisfies the power-sharing requirement. On the other hand, the control algorithm autonomously forces the solar PV to operate at the maximum power point if the solar PV output is lower than the power-sharing requirement. Various operating scenarios have been simulated to appreciate the effectiveness of the proposed control scheme for ensuring the load-power sharing and maintaining the voltage and frequency stability of the islanded microgrid containing a 100% solar PV generation.

scholarly journals Gear Shift Coordinated Control Strategy Based on Motor Rotary Velocity Regulation for a Novel Hybrid Electric Vehicle

2021 ◽  
Vol 11 (24) ◽  
pp. 12118
Author(s):  
Qicheng Xue ◽  
Xin Zhang ◽  
Cong Geng ◽  
Teng Teng
Keyword(s):  
Electric Vehicle ◽  
Control Strategy ◽  
Hybrid Electric Vehicle ◽  
Control Algorithm ◽  
Sliding Friction ◽  
Coordinated Control ◽  
Velocity Control ◽  
Gear Shift ◽  
Shift Quality ◽  
Hybrid Electric

This paper proposes a novel hybrid power system to improve the shift quality of a hybrid electric vehicle (HEV). After selecting a typical shift scheme, the study focused on the motor rotary velocity control algorithm and coordinated control strategy for the motor and clutch. The effects of various control algorithms on different target rotary velocities were analyzed, and a proportional-integral-derivative (PID)–bang-bang–fuzzy compound intelligent algorithm for a motor rotary velocity control system was investigated. In addition, to address the problems of the long synchronizing time required for the rotary velocity and large sliding friction work, which affect the shift quality during the process of engaging the clutch, a coordinated control strategy for the motor rotary velocity and clutch oil pressure was investigated. The research results showed that, compared with a gear shift coordinated control strategy based on a PID control algorithm, the strategy based on the PID–bang-bang–fuzzy compound intelligent control algorithm proposed here reduced the shift time and clutch slipping friction work by 35.7% and 19.2%, respectively.

A new coordinated control strategy for tracked vehicle ride comfort

2017 ◽  
Vol 232 (3) ◽  
pp. 330-341 ◽  
Author(s):  
Jianfeng Li ◽  
Amir Khajepour ◽  
Yanjun Huang ◽  
Hong Wang ◽  
Chen Tang ◽  
...  
Keyword(s):  
Control Strategy ◽  
Degrees Of Freedom ◽  
Target Location ◽  
Ride Comfort ◽  
Sliding Mode ◽  
Coordinated Control ◽  
Magnetorheological Damper ◽  
Vertical Acceleration ◽  
Tracked Vehicle ◽  
Multi Body

To improve tracked vehicle ride comfort and minimize weapon's vibration, a coordinated control strategy is developed for tracked vehicles' semi-active suspension systems. A model with eight degrees-of-freedom for a tracked vehicle equipped with magnetorheological dampers is established, and is followed by the formulation of a sliding mode controller. The proposed control algorithm is a localized-based controller that can change its target location in the tracked vehicle to where it is needed most. A co-simulation system model including a six-wheel tracked vehicle multi-body dynamics model, coordinated control strategy, and magnetorheological damper force allocator is developed to analyze the ride performance under bump and random road excitations. The simulation results demonstrate that the proposed strategy is very effective in improving the vehicle's ride performance and is much better than the traditional skyhook controllers. The innovation of this paper can be concluded as the coordinated control strategy can simultaneously improve vertical acceleration and pitch acceleration for the hull, which is of great importance for combat situations.

scholarly journals Super-twisting sliding mode based nonlinear control for planar dual arm robots

2020 ◽  
Vol 9 (5) ◽  
pp. 1844-1853
Author(s):  
Tung Lam Nguyen ◽  
Huu Tinh Vu
Keyword(s):  
Control Strategy ◽  
Sliding Mode ◽  
Numerical Study ◽  
Sliding Mode Controller ◽  
Controller Performance ◽  
Tracking Ability ◽  
Rotational Motions ◽  
Dual Arm Robot ◽  
Twisting Algorithm ◽  
Dual Arm

In this paper, a super-twisting algorithm sliding mode controller is proposed for a planar dual arm robot. The control strategy for the manipulator system can effectively counteract chattering phenomenon happened with conventional sliding mode approach. The modeling is implemented in order to provide the capability of maneuvering object in translational and rotational motions. The control is developed for a 2n-link robot and subsequently simulations is carried out for a 4-link system. Comparative numerical study shows that the designed controller performance with good tracking ability and smaller chattering compared with basic sliding mode controller. 

scholarly journals Event-Triggered Adaptive Sliding Mode Attitude Containment Control for Microsatellite Cluster under Directed Graph

2021 ◽  
Vol 2021 ◽  
pp. 1-25
Author(s):  
Fengzhi Guo ◽  
Shijie Zhang ◽  
Tingting Zhang ◽  
Anhui Zhang
Keyword(s):  
Control Problem ◽  
Control Strategy ◽  
Control Algorithm ◽  
Sliding Mode ◽  
Steady States ◽  
Containment Control ◽  
Directed Topology ◽  
Adaptive Sliding Mode ◽  
Microsatellite Cluster ◽  
Event Triggered

In order to investigate the attitude containment control problem for a microsatellite cluster, an event-triggered adaptive sliding mode attitude containment control algorithm is proposed for the satellite cluster flight system under directed topology, so that attitude of followers asymptotically converges to the convex hull formed by the leaders’ orientations. At first, the event-triggered control strategy is introduced into the attitude containment control problem for the microsatellite cluster. The triggering condition consisting of state-dependent and time-dependent function is designed to adjust control period and avoid the Zeno behaviour. When the function value meets the triggering condition, the event is triggered, state information is sampled, control law is computed, and actuators are updated, while the control action performed in nontriggering time is the same as the previous triggering instant. Then, in the presence of model uncertainties and external disturbances, an event-triggered adaptive sliding mode attitude containment control algorithm is presented under directed topology, and sufficient and necessary conditions for the followers to enter into the target area formed by the leaders are given. Furthermore, cell partitions from graph theory are employed to investigate the influence of information topology on steady states of followers, which provides theoretical basis for orientation design of cluster satellites. Finally, simulation results show that the proposed control strategy could reduce control execution frequency, as well as ensure the similar control performance with the time-triggered one, and followers belonging to the same cell have the same steady states.

Review of Vehicle Active Safety Systems and their coordinated control

2020 ◽  
Vol 13 ◽  
Author(s):  
Zixiang Zhao ◽  
Xiaobin Fan
Keyword(s):  
Control System ◽  
Angular Velocity ◽  
Control Strategy ◽  
Sliding Mode ◽  
Control Strategies ◽  
Slip Rate ◽  
Coordinated Control ◽  
Active Safety ◽  
Vehicle Active Safety ◽  
And Control

Background: All the time, the safety of the vehicle has been valued by all the world's parties, whether it is now or in the future, the automobile safety issue is the hotspot and focus of the research by experts and scholars. The continuous increase of car ownership brings convenience to people's life and also poses a threat to people's life and property security. Vehicle active safety system is the hotspot of current research and development, which plays an important role in automobile safety. Firstly, the vehicle active safety technology and its development situation was introduced, then Ref. review was carried out about Anti-Lock Brake System (ABS), Electronic Brake force Distribution (EBD/CBC), Brake Assist System (BAS/EBA/BA), Traction Control System (TCS/ASR), Vehicle Stability Control (VSC/ESP/DSC), etc. At present, there are many patents on the control of each subsystem, but few patents on the integrated control for the active safety of vehicles. Objective: The main contents of this paper are as follows: the control strategies and methods of different active safety systems, how to improve the stability of vehicle control and ensure the effectiveness of active safety system control. It provides a reference for the development of active safety control technology and patent. Methods: Through the analysis of different control algorithms and control strategies of Anti-lock and braking force distribution systems, it is pointed out that the switching of EBD/ABS coordinated control strategy according to slip rate can make full use of slip rate and road adhesion coefficient to improve the safety of the system. For the BAS, the slip problem is solved through the combination of Mechanical Assistant Braking System (MABS) and Electronic Braking Assistant (EBA) system by measuring the distance of the vehicle ahead and the speed of the vehicle ahead. The optimal slip rate control is realized by different control algorithms and control strategies of traction control system. It is pointed out that the adaptive fuzzy neural controller should be used to control the yaw angular velocity and centroid side angle of Electronic Stability Program (ESP), which has a good effect on maintaining vehicle stability. A sliding mode variable structure controller combined with constant speed control and approach law control is used to control the yaw moment. Results: Through the coordinated control strategy of EBD/ABS, the slip rate and road adhesion coefficient were fully utilized by switching according to slip rate. The problem of sliding slope is solved by MABS with EBA system. The ESP should use adaptive fuzzy neural controller to control the yaw angular velocity and centroid side angle, and adopt the joint sliding mode variable structure controller which combines the ABS control and the yaw moment control. Through the optimal control theory, the coordinated control of each subsystem can significantly improve the driving stability, riding comfort, fuel economy and so on. Conclusion: This adopt different control strategy and control algorithm for different active safety control system and make full use of tire-road friction coefficient and slip ratio optimal slip ratio, then it realized accurate control of control variables such as yawing angular velocity, centroid side-slip angle, yawing moment and finally ensure the vehicle braking stability, robustness of the controller and the lateral stability of vehicle.

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