Motor Control Strategies Research Articles

Design and position control of a robotic brace dedicated to the treatment of scoliosis

AbstractThis paper’s content focuses on designing and prototyping a robotic brace dedicated to treating scoliosis. Scoliosis is an abnormal spinal curvature affecting 1–3% of children and constitutes a major therapeutic problem. In moderate cases of deformity, passive brace treatment is performed. However, this approach can lead to important patient discomfort. So, we propose a robotic solution providing greater mobility and the possibility of adapting the procedure to each patient. The robotic brace we built and tested is composed of three specific rings adapted to the patient’s torso. Each independent module of two consecutive rings is movable through a Stewart–Gough platform-type mechanism. As the robotic brace is lightweight, it brings better portability and improves the patient’s comfort.The first part of the paper shows the state of the art of bracing techniques: from passive to active orthoses. Next, the mechatronics of the device is detailed, and the robot’s kinematic models are developed. The motion control principle is given. In the last part, motion tests were administered with a healthy human to validate the brace architecture choice and its position and motion control strategies.

Full prediction cascade control of permanent magnet toroidal motor with time-varying parameters

This paper presents the modeling and predictive control of permanent magnet toroidal motor (PMTM). Based on the spatial structure characteristics and working principle of toroidal motor, the time-varying inductance parameters are derived. The nonlinear mathematical model of toroidal motor is established in rotating coordinate system. The output fluctuation of the toroidal motor is analyzed. To improve the output performance of toroidal motor, the full predictive cascade speed and current control (F-MPC) strategy for toroidal motor is proposed. For F-MPC of toroidal motor, the finite control set model predictive current control (FCS-MPCC) strategy with delay compensation is adopted in current inner loop, and the deadbeat model predictive speed control (DB-MPSC) strategy is adopted in speed outer loop. Meanwhile, to achieve DB-MPSC, the reduced-order Luenberger observer is designed to obtain load torque in real time. F-MPC is the combination of current-speed prediction and Luenberger observer; it can overcome the limitation of excessive parameter adjustment of traditional cascade PI (Proportional Integral) controller. The simulation results show that compared with FOC (Field Oriented Control) and FCS-MPCC, F-MPC can improve the dynamic response and anti-interference performance of toroidal motor, and it can also reduce the fluctuation of output speed and torque significantly.

Dynamic Modeling and Motion Control Strategy of Cable-Driven Cleaning Robot for Ship Cargo Hold

Ship cargo-hold cleaning is a low-efficiency and high-risk operation in marine industry, which is generally carried out manually, putting the workers in danger. To improve the efficiency and safety of ship cargo-hold cleaning, a C-DCR is proposed in this article. Most research on the dynamics and control of CDPRs has focused on the scenarios with fixed bases; however, the effect of moving-base excitation on the end-effector is largely ignored. In this article, the dynamic model is established based on Lagrange method considering the ship motion and external disturbance, in which the motor model is considered. On this basis, for the high-speed maneuverability of the C-DCR, a modified PD feedforward tracking controller was proposed. Furthermore, the stability of the controller was proved with the Lyapunov Stability Theory. To keep the cable in tension at all times, the tensions are optimized based on the minimum 2-norm method. The simulation results show that the error mean of position is 0.22 m and the angular error mean is 2.8° under ship motion and external disturbance, indicating that the C-DCR has stable, smooth and bounded tracking performance, which will ensure the accuracy of the cleaning operation.

Linear manipulator: Motion control of an n-link robotic arm mounted on a mobile slider

Linear manipulators are versatile linear robotics systems that can be reprogrammed to accommodate product changes quickly and are flexible to meet unique requirements. Such robotic systems tend to have higher accuracy, making them the perfect automation solution for those mundane, repetitious tasks. With the demand for linear systems in real-life applications expanding consistently, this paper addresses motion planning and control (MPC) of a new modified unanchored linear manipulator consisting of an n-link robotic arm mounted on a mobile slider along a rail. Using the method of the Lyapunov-based Control Scheme (LbCS), new centralized acceleration-based controllers are designed for the navigation of the system to an unreachable target. Via the scheme, the unanchored manipulator can perform assigned tasks with enhanced reachability. The limitations and singularities of the linear manipulator are treated as artificial obstacles in this motion control scheme. The robotic arm manipulator utilized in this research can reposition its base link to a desired location in the workplace due to changes in work requirements. The effectiveness of the motion planner and the resulting acceleration-based control laws are validated numerically using the Runge-Kutta Method and illustrated via computer simulations. The controllers devised in this research can solve specific and targeted motion control problems of smart cities' modern mechanical systems. The unanchored linear manipulator could be used in various disciplines where pick-and-place, assembly, material handling, and surgical procedures are required.

Research on compound control strategy of sensorless permanent magnet synchronous motor

Research on compound control strategy of sensorless permanent magnet synchronous motor

Research on compound control strategy of sensorless permanent magnet synchronous motor

Research on compound control strategy of sensorless permanent magnet synchronous motor

Vector control strategies for synchronous reluctance motor: constant current control, MTPA, MTPW and MPFC

Vector control strategies for synchronous reluctance motor: constant current control, MTPA, MTPW and MPFC

Active Current Sensor Fault-Tolerant Control of Induction Motor Drive with Online Neural Network-Based Rotor and Stator Resistance Estimation

Abstract This article presents an active current sensor (CS) fault-tolerant control (FTC) strategy for induction motor (IM) drive with adaptation of rotor and stator resistances. The stator current estimator with online adaptation of resistance parameters was applied for the reconstruction of missing current signals. A model reference adaptive system (MRAS), based on a neural network (NN), was used to estimate the rotor resistance. Additionally, stator resistance estimation was applied based on ratio index. The use of such a solution allowed for a significant increase in the quality of stator current reconstruction, which is particularly important for the design of CS fault detection (FD) and compensation algorithms. A wide range of simulation studies have been carried out for different operating conditions of the IM drive. The results showed that applying rotor and stator resistance estimation can improve the quality of stator current estimation by up to approximately 95% under rated operating point. The study was carried out for nominal and low speeds, with two, one, and without healthy CS.

A sensorless stable V/f control of SPMSM based on constant power factor control with a novel MTPA tracking

The paper presents a sensorless stable V/f control strategy of surface permanent magnet synchronous motor (SPMSM), where the maximum torque per ampere (MTPA) condition is satisfied by controlling the d-axis current to zero. However, to directly control the d-axis current, it is necessary to know the exact rotor position, which is not possible in sensorless V/f control. Based on this fact, a constant power factor (CPF) control loop in voltage vector reference frame dvqv with a novel MTPA tracking according to a look-up table (LUT) was developed. The LUT was created based on a set of experimental measurements to store the motor power factor where MTPA is reached. The proposed stable V/f control strategy shows an accurate MTPA tracking of SPMSM in the entire operational range verified by experiments.

Position Sensorless Control for PMSM Drives With Single Current Sensor

The aim of this article is an attempt to provide a more credible control mode or a fault-tolerant control strategy for permanent magnet synchronous motor (PMSM) drives when an unexpected failure occurs to the current or position sensor. Considering that, a position sensorless control method that uses only one current sensor is proposed. Different from a traditional position sensorless control scheme that utilizes additional current sensors to obtain information of multiple phase currents, only a single current sensor (SCS) arranged on one of the current branches is included among the whole control circuit. Three-phase currents are reconstructed by sequentially sampling the SCS under specific voltage vectors, and directly employed for motor position estimation. A nonlinear position observer established according to the gradient descent is adopted. Focusing on the special current-acquisition pattern in this article, a step-size optimization method based on golden section search is proposed to minimize position estimation error. The experimental results reveal that the method in this article is comparable to the traditional full-current-sensor method in terms of position estimation, which confirms the fault-tolerant capability as one certain sensor of the control structure malfunctions.

Fast Finite-Time Tracking Control Strategy for Permanent Magnet Synchronous Motor

Fast Finite-Time Tracking Control Strategy for Permanent Magnet Synchronous Motor

Vector control strategies for synchronous reluctance motor: constant current control, MTPA, MTPW and MPFC

Vector control strategies for synchronous reluctance motor: constant current control, MTPA, MTPW and MPFC

Optimisation of Model Predictive Torque Control Strategy with Standard and Multi-Objective Genetic Algorithms

Abstract In this paper, the flux error-related weighting factor (WF) of the predictive torque control (PTC) strategy for induction motor (IM) control is optimised by a standard genetic algorithm (SGA) through speed errors only and multi-objective genetic algorithm (MOGA) through torque and flux errors. This paper compares the performances of both optimisation methods. Compared to MOGA, SGA offers a straightforward way to select WF and does not need a decision-making method to choose a final solution. But MOGA considers the given problem in a multi-objective way and directly optimises the control objectives of the PTC strate-gy. Comparisons are made over the flux and torque ripples, total harmonic distortion of stator phase current, and average switching frequency for different operating conditions. Simulation results show that both methods choose a close WF value. Consequently, SGA stands out in the optimisation of the PTC strategy with its simple structure.

Sensorless Control of PMSM Drives Using Reduced Order Quasi Resonant-Based ESO and Newton–Raphson Method-Based PLL

This article proposes a novel sensorless control strategy for permanent magnet synchronous motor drives using reduced order quasi resonant-based extended state observer (ROQR-ESO) and Newton–Raphson method-based phase-locked loop (NRM-PLL). Due to the low-pass filtering characteristics, the conventional linear extended state observer (LESO) is not adequately able to track the fast-varying back electromotive forces (BEMFs). On this basis, the ROQR-ESO, which plants a ROQR controller into the internal model of conventional LESO, is presented to obtain BEMFs without phase lag. Moreover, the NRM-PLL, regarded as an improved finite position set-PLL, is proposed. After the rotor position is divided into four parts by utilizing a position quartering method, the extremely accurate rotor position can be obtained only by three iterations. In this method, no parameters need to be adjusted and great dynamic response can be achieved. The capacity of the proposed scheme is verified on a 750 W permanent magnet synchronous motor drive platform.

Adaptive neural control for chaotic permanent magnet synchronous motor with asymmetric input saturation

This paper develops an adaptive neural control scheme for chaotic permanent magnet synchronous motor with asymmetric input saturation and full-state constraints. To solve the state constrain problem, a barrier Lyapunov function is introduced. Then, a sliding-mode differentiator is designed to avoid the “explosion of complexity” issue. A simulation example is given to verify the validity of the proposed scheme.

The progressive control of foot-and-mouth disease (FMD) in the Republic of Kazakhstan: Successes and challenges.

Foot-and-mouth disease (FMD) has historically caused far-reaching economic losses to many regions worldwide. FMD control has been problematic, and the disease is still prevalent in many West and Central Asia countries. Here, we review the progress made by Kazakhstan in achieving freedom from FMD and discuss some of the challenges associated with maintaining the FMD-free status, as evidenced by the occurrence of an outbreak in 2022. A combination of zoning, movement control, vaccination, and surveillance strategies led to eliminating the disease in the country. However, the circulation of the FMD virus in the region still imposes a risk for Kazakhstan, and coordinated strategies are ultimately needed to support disease elimination. The results presented here may help design effective pathways to progressively eliminate the disease in West and Central Asia while promoting the design and implementation of regional actions to support FMD control.

Research on Motion Control Strategy of Flexible Manipulator Based on Swarm Intelligence Optimization

Research on Motion Control Strategy of Flexible Manipulator Based on Swarm Intelligence Optimization

СИСТЕМА АВТОМАТИЧЕСКОГО СЛЕЖЕНИЯ ЗА СОЛНЦЕМ

The possibility of implementing software based on a mathematical model of the Earth's motion around the Sun for a solar panel drive control system is being considered in order to increase the efficiency of the solar battery and bring it closer to application in industrial conditions. The method of conducting an experiment on the influence of the angle of inclination of the solar panel on the output power is described, and a stepper motor control scheme for the orientation of the solar panel in space is developed.

Development and computer implementation of the motion model and control algorithms of a hybrid multicopter

Among modern unmanned aerial vehicles, a special place is occupied by hybrid multicopters, in which internalcombustion engines are used along with electric motors to create lift. They can carry a larger load for a longertime. But the combination of a more powerful engine with less powerful ones, the variability of the inertialcharacteristics during the flight, significantly complicate the dynamics of such an object and its control. Therefore,there is almost no practical experience in operating such devices, which is the motivation for research anddevelopment in this area. The article deals with a helicopter-type multicopter with five electric motors (4+1 on thetail) and a central internal combustion engine. A mathematical description of the dynamics and kinematics of the
 apparatus has been created for the purpose of computer simulation of a controlled flight. The description takes intoaccount all internal dynamic factors and is given simultaneously with respect to the inertial and associatedcoordinate systems, which simplifies the solution of the flight control problem as much as possible. For the latter, amultiloop motion control scheme with the help of motors has been developed. The algorithms are based on thedecomposition of the problem under the conditions of typical motion modes and the modal control method, whichprovides the desired quality of transient processes. A universal automaton for the interaction of control algorithmsfor each engine is described. A typical flight program is simulated, containing climb, course change, following tothe set hovering point and landing under it. The presented results showed the performance of the algorithms anddetermined the directions for further research. The results in the form of a mathematical model, recommendationsfor task decomposition and specific algorithms can be used in the process of designing a hybrid multicopter controlsystem.

Altered muscle recruitment patterns during isometric shoulder abduction in individuals with chronic upper trapezius pain: a cross sectional study

BackgroundUpper trapezius (UT) pain with myofascial trigger points (MTrPs) can affect movement at the glenohumeral joint as well as at the scapulothoracic joint. The investigation of muscle recruitment patterns can discern motor control strategies. The purpose of this study was to compare shoulder muscle recruitment patterns and muscle activity according to various loads between individuals with and without chronic UT pain.MethodsIn this cross-sectional study, twenty-four participants that had UT pain with MTrPs and sex, age, body weight matched 24 controls with no UT pain were recruited. Surface EMG electrodes were attached to the UT, the serratus anterior (SA), the lower trapezius (LT) and the middle deltoid (MD). All participants performed isometric shoulder abduction with a load of 25%, 50%, or 75% of the maximum strength at 60° of shoulder abduction. The EMG activity, the activity ratio (SA/UT, LT/UT, MD/UT), and the relative contribution of each muscle activity were calculated.ResultsMD activity was significantly decreased in the UT pain group compared to that in the control group (p < 0.05). The EMG activity ratio of SA/UT (p < 0.025) and the relative contribution of SA activity to shoulder abduction (p < 0.05) were significantly greater in the UT pain group than in the control group in the 25% loading condition.ConclusionThe results of present study showed that UT pain with MTrPs may increase the relative contribution of SA activity and decrease MD activity at low loads. Altered recruitment patterns of scapular upward rotators can be altered in the proper scapular position, which results in decreased MD activity. Clinicians should consider altered recruitment patterns when managing UT pain.Trial registrationClinical Research Information Service: Clinical Research Information Service (KCT0007370; 08/06/2022).