This paper presents a new systematic control and fail-safe design methodology for a four-corner closed-loop air suspension (CLAS) system. The proposed control algorithm consists of "system control" determini...
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This paper presents a new systematic control and fail-safe design methodology for a four-corner closed-loop air suspension (CLAS) system. The proposed control algorithm consists of "system control" determining the target heights of the four corners of the vehicle body from driving conditions and from the driver's commands and "actuator control" achieving the target heights by controlling actuators. A sliding-mode control with phase-compensated feedback signal is applied as the main part of the system control. With the use of the sliding-mode control, the proposed system control can improve control accuracy and robustness against delays and disturbances as well as reduce the bounce oscillation of the vehicle body. This paper proposes a stepwise height control as the actuator control to overcome the limited power of the production CLAS system. The stepwise height control adjusts the front corners and the rear corners alternately until the four corners reach their corresponding target heights. A fail-safe algorithm (FA) is also proposed to provide the fault detection (FD), diagnosis, and management of the CLAS. In particular, a model-based FD method for the pressure sensor and the height sensors, which are critical components in the CLAS control system, has been proposed. A mathematical model of a CLAS system is developed for algorithm development and simulation. The proposed control algorithm and FA are verified by simulations and actual vehicle tests.
This paper proposes an artificial intelligence (AI)-based new control algorithm for a self-balancing quadruped robot. A quadruped robot is a good example of a redundant degree-of-freedom (DOF) system and is designed f...
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This paper proposes an artificial intelligence (AI)-based new control algorithm for a self-balancing quadruped robot. A quadruped robot is a good example of a redundant degree-of-freedom (DOF) system and is designed for locomotion over extreme terrain conditions. Even though a relevant control algorithm exerts a great effect on the performance of the locomotion control of quadruped robots, controlling them is difficult and complex because of the redundant DOF and interlocked movement of their four legs. This paper presents an effective control algorithm that can replace the typical analysis-based control theory, including inverse kinematics, differential equations of motion, and governing equations, which is based on reinforcement learning (RL) and artificial neural network (ANN). RL generates the training data to train the ANN model, and the trained ANN model is finally used to control a quadruped robot. The proposed AI-based robot-control algorithm is validated experimentally using a customized test-bed and a self-balancing quadruped robot. The results show that the proposed method is a promising new control algorithm that can replace the mathematically incomprehensible robot-control system.
The power steering system for vehicles is becoming essential for supporting the driver's steering efforts, especially for manoeuvring in parking lots. Although hydraulic power steering has been widely used for yea...
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The power steering system for vehicles is becoming essential for supporting the driver's steering efforts, especially for manoeuvring in parking lots. Although hydraulic power steering has been widely used for years, it is not efficient enough. The problems associated with a hydraulic power steering system can be solved by using a motor-driven power steering (MDPS) system. In this study, a dynamic model and a control algorithm for a ball screw type MDPS system have been derived and analysed by using discrete modelling technology. To improve the comfort level while steering and power steering characteristics, an additional scheme is added to the conventional power boosting control algorithm. Through simulations, the effects of the control gain on the steering angle gain in the frequency domain were verified. The steering returnability and steering torque phase lag in on-centre handling tests were also verified.
In this paper, the authors suggest a new control algorithm for a three-phase four-wire photovoltaic (PV) inverter with imbalance load compensation function using conventional proportional-integral (PI) controllers. Th...
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In this paper, the authors suggest a new control algorithm for a three-phase four-wire photovoltaic (PV) inverter with imbalance load compensation function using conventional proportional-integral (PI) controllers. The maximum power of PV panel is calculated by the MPPT control loop. The reference varying signals of current controllers are transformed to two different rotating frames where they become constant signals. Then simple PI controllers are applied to achieve zero steady-state error of the controllers. The proposed control algorithm are modeled and simulated with imbalance load configuration to verify its performance. The simulation results show that the maximum PV power is transferred to the grid and the imbalance power is compensated successfully by the proposed control algorithm. The inverter has a fast response (similar to 4 cycles) during the transient period. The proposed control algorithm can be effectively utilized to the three-phase four-wire inverter with imbalance load compensation function.
This paper focuses on the robustness analysis of a simple (second-order) control algorithm for data transfer in high-speed networks. The model under consideration (derived using a fluid approximation technique) can be...
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This paper focuses on the robustness analysis of a simple (second-order) control algorithm for data transfer in high-speed networks. The model under consideration (derived using a fluid approximation technique) can be found in lzmailov (SIAM J. Contr. Optimiz. 34 (1996) 1767). The novelty of the approach lies in characterizing the stability of the scheme in the delay-parameter space (where the delays correspond to the control-time interval, and to the round-trip time, respectively). Thus, we shall compute some delay-insensitive measures for the algorithm which give upper and lower bounds for the uncertainty in the knowledge of the round-trip times. (C) 2002 Published by Elsevier Science Ltd.
In lunar exploration, lunar-based equipment assumes the responsibility of mobility and transportation during the construction of unmanned lunar base. Legged robots are an important form of the lunar-based equipment du...
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In lunar exploration, lunar-based equipment assumes the responsibility of mobility and transportation during the construction of unmanned lunar base. Legged robots are an important form of the lunar-based equipment due to their mobility and terrain adaptability. However, the influence of lunar terrain and lunar soil cannot be ignored when it comes to studying the mobile stability of lunar-based equipment. Utilizing the dynamic model of the robotic leg, this study proposes a new robust control algorithm, MBC (Model-Based with Continuous expression) algorithm, for lunar-based equipment's robotic leg, and its effectiveness is established through experimentation and theoretical validation with the Lyapunov second method. In the design and verification, the contact force of lunar soil and the lunar environment with low gravity are considered, indicating the applicability of the proposed MBC method in special lunar scenarios. Compared to the conventional PD (Proportional-Differential) and MPD (Model-Based Proportional-Differential) techniques, MBC robust algorithm ultimately demonstrates superior stability and rapidity with a smaller steady state error. (c) 2024 COSPAR. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
An algorithm for reducing the influence of geometrical, thermal, kinematic and stiffness errors in five-axis machine tool components on the desired tool position and orientation is given. This new algorithm is based o...
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An algorithm for reducing the influence of geometrical, thermal, kinematic and stiffness errors in five-axis machine tool components on the desired tool position and orientation is given. This new algorithm is based on the calculation of the cutting tool error matrix for orthogonal machine tools. In the new model of this matrix, all angular errors of the machine links are considered as infinitesimal rotations. The error matrix is a function of the commanded machine component positions and the errors in these positions. To correct errors in the three translational and two angular tool positions, a matrix of commanded tool position and orientation is multiplied by the inverse error matrix in every period of the tool trajectory interpolation. This corrected matrix of the tool position and orientation provides the inverse kinematics used for calculation of the successive links positions required for achieving the given tool trajectory. The control algorithm for five-axis machine tools with the error compensation is implemented both in the CNC system and in the postprocessor. The proposed algorithm is applied on a vertical five-axis turning centre with two translational and three rotational axes. Twenty-four errors that could cause inaccurate machining are recognised on this machine. The machine links and their coordinate frames are denoted using the Denavit-Hartenberg parameters.
In the traditional proportion integral differential (PID) power steering stability modelling and control algorithm, the road control process lacks auxiliary control, the real-time performance is poor, and the stabilit...
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In the traditional proportion integral differential (PID) power steering stability modelling and control algorithm, the road control process lacks auxiliary control, the real-time performance is poor, and the stability is low. In view of this situation, a stability modelling and control algorithm of electric vehicle steering system is proposed. The simulation models of steering system, motor system and frame system are established by using the simulation tools of MATLAB software. The test results show that the lateral acceleration control algorithm of electric vehicle is -0.4 to -0.72 g, 17.5 degrees/s and 22 degrees/s respectively under the control of input angle of 3 degrees/s to 17.5 degrees/s, stability of 22 degrees/s, stability of 0.4 to -0.3 g and -0.33 to -0.72 g.
Pilots of modern combat aircraft are exposed to the devastating effects of high acceleration forces. The pilots' ability to perform tasks under these extreme flight conditions must be examined. A centrifuge motion...
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Pilots of modern combat aircraft are exposed to the devastating effects of high acceleration forces. The pilots' ability to perform tasks under these extreme flight conditions must be examined. A centrifuge motion simulator for pilot training is designed as a 3DOF manipulator with rotational axes. Through rotations about these axes, acceleration forces that act on aircraft pilots are simulated. Because of the possibilities of present actuators, it is notably difficult to produce a centrifuge that can realise all of the desired changes of the acceleration forces completely accurately. For this reason, it is necessary to make a compromise in the centrifuge's design with regard to the motor choices and link designs. A new control algorithm that contains a new algorithm for the inverse dynamics of the robots (based on the recursive Newton-Euler algorithm) and that accounts for the possible motor actions has been developed in this study. This algorithm first calculates the successive actuator torques of the links, which are required for the given motion during each interpolation period. Next, the algorithm checks whether actuators can achieve these torques, and if they cannot, it calculates the maximal successive link angular accelerations that motors can achieve. Based on this, control unit sends appropriate control inputs. As a result, the quality of the motion control is improved, and a precise calculation of the forces and the moments that act on the centrifuge links (which is necessary to calculate the link strengths) is performed. (C) 2014 Elsevier Ltd. All rights reserved.
In order to study the advanced divertor physics and support the high performance plasma operation, a new control algorithm has been developed for the advanced divertor configuration (snowflake and tripod) on HL-2M. Th...
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In order to study the advanced divertor physics and support the high performance plasma operation, a new control algorithm has been developed for the advanced divertor configuration (snowflake and tripod) on HL-2M. The response of the PF currents due to the change of the X-points positions has been established in this algorithm. The two X-points of the snowflake or tripod configuration can be independently controlled both at the radial and the vertical direction by this control algorithm. With this control algorithm, the preliminary simulation results have been achieved. Furthermore, with this algorithm the exact snowflake configuration can be obtained from the tripod configuration by control the X-points positions.
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