Incremental PID Control Research Articles

Adaptive Network-Based Fuzzy Inference System–Proportional–Integral–Derivative Controller Based on FPGA and Its Application in Radiofrequency Ablation Temperature Control

The radiofrequency ablation temperature system is characterised by its time-varying, non-linear, and hysteretic nature. The application of PID controllers to the control of radiofrequency ablation temperature systems has a number of challenges, including overshoot, dependence on high-precision mathematical models, and difficulty in parameter tuning. Therefore, in order to improve the effectiveness of radiofrequency ablation temperature control, an adaptive network-based fuzzy inference system combined with an incremental PID controller was used to optimise the shortcomings of the PID controller in radiofrequency ablation temperature control. At the same time, the learning rate at the time of updating the consequence parameters was set by segmentation to solve the problem of poor control accuracy when the ANFIS-PID controller is implemented based on FPGA fixed-point decimals. Based on FPGA-in-the-loop simulation experiments and ex vivo experiments, the effectiveness of the ANFIS-PID controller in the temperature control of radiofrequency ablation was verified and compared with the PID controller under the same conditions. The experimental results show that the ANFIS-PID controller has a superior performance in terms of tracking capability and stability compared with the PID controller.

Establishment of the microscope incubation system and its application in evaluating tumor treatment effects through real-time live cellular imaging.

Introduction: Long-term imaging of live cells is commonly used for the study of dynamic cell behaviors. It is crucial to keep the cell viability during the investigation of physiological and biological processes by live cell imaging. Conventional incubators that providing stable temperature, carbon dioxide (CO2) concentration, and humidity are often incompatible with most imaging tools. Available commercial or custom-made stage-top incubators are bulky or unable to provide constant environmental conditions during long time culture. Methods: In this study, we reported the development of the microscope incubation system (MIS) that can be easily adapted to any inverted microscope stage. Incremental PID control algorithm was introduced to keep stable temperature and gas concentration of the system. Moreover, efficient translucent materials were applied for the top and bottom of the incubator which make it possible for images taken during culture. Results: The MIS could support cell viability comparable to standard incubators. When used in real time imaging, the MIS was able to trace single cell migration in scratch assay, T cell mediated tumor cells killing in co-culture assay, inflation-collapse and fusion of organoids in 3D culture. And the viability and drug responses of cells cultured in the MIS were able to be calculated by a label-free methods based on long term imaging. Discussion: We offer new insights into monitoring cell behaviors during long term culture by using the stage adapted MIS. This study illustrates that the newly developed MIS is a viable solution for long-term imaging during in vitro cell culture and demonstrates its potential in cell biology, cancer biology and drug discovery research where long-term real-time recording is required.

Nonlinear Control of Magnetically Coupled Rodless Cylinder Position Servo System

Magnetically coupled rodless cylinders are widely used in the coordinate positioning of mechanical arms, electrostatic paintings, and other industrial applications. However, they exhibit strong nonlinear characteristics, which lead to low servo control accuracy. In this study, a mass-flow equation through the valve port was derived to improve the control performance, considering the characteristics of the dynamics and throttle-hole flow. Subsequently, a friction model combining static, viscous, and Coulomb friction with a zero-velocity interval was proposed. In addition, energy and dynamic models were set for the experimental investigation of the magnetically coupled rodless cylinder. A nonlinear mathematical model for the position of the magnetically coupled rodless cylinder was proposed. An incremental PID controller was designed for the magnetically coupled rodless cylinder to control this system, and the PID parameters were adjusted online using RBF neural network. The response results of the PID parameters based on the RBF neural network were compared with those of the traditional incremental PID control, which proved the superiority of the optimization control algorithm of the incremental PID parameters based on the RBF neural network servo control system. The experimental results of this model were compared with the simulation results. The average error between the established model and the actual system was 0.005175054 (m), which was approximately 2.588% of the total travel length, demonstrating the accuracy of the theoretical model.

Optical flow-based closed-loop control of a multi-degree-of-freedom clamping-type ultrasonic motor.

Rotor speed and position detection are integral parts of the closed-loop control system for multi-degree-of-freedom (multi-DOF) ultrasonic motors. The non-contact speed detection method is important for the high-precision control of the spherical rotor. This paper proposes a closed-loop control method based on an optical flow sensor for the velocity-position control of a multi-DOF clamping-type ultrasonic motor. The optical flow information is analyzed using the conical L-K optical flow algorithm to obtain the rotor speed and position. An incremental PID control method is used to perform dual closed-loop positioning control of the motor regarding speed and position. An experimental platform for the optical flow sensor is designed, and the method's feasibility is verified experimentally.

Fuzzy neural network PID control design of camellia fruit vibration picking manipulator

Due to the growth characteristics of the flowers and fruits of camellia in the same period, the vibrating camellia fruit picking machine needs to ensure the constant rotational speed of the vibrating hydraulic motor when the picking mechanism is operating, to achieve a constant vibration frequency, to ensure that the camellia fruit can smoothly fall off the branches through vibration. In contrast, the camellia fruit does not fall off. In this regard, this paper deduced the state space equation of the camellia fruit picking machine’s valve-controlled vibrating hydraulic motor system and designed a fuzzy wavelet neural network PID controller (FWNN PID controller) based on the traditional incremental PID control principle. Then the designed vibration picking manipulator control system was simulated under no-load, 5 s load conditions, and load start conditions with MATLAB/Simulink, a general PID controller and a fuzzy RBF neural network PID controller (FRBFNN PID controller) were used to contrast with it. The results show that the general PID controller has a slow response speed and poor robustness, while fuzzy neural network PID controllers (including FWNN PID controller and FRBFNN PID controller) have a fast response speed and strong robustness, which can well meet the requirements of a specific vibration frequency. Finally, a field test was carried out. The results show that the FWNN PID control is better than the FRBFNN PID control. Furthermore, the FWNN PID controller obviously reduced the drop rate of camellia flowers within 6% while ensuring the picking efficiency above 90%, which can well meet the needs of the camellia fruit picking operation.

Simulation Study on Digital Control Model of Fiber Optic Gyro SLD Light Source

Fiber Optic Gyroscope is an angular velocity sensitive device based on Sagnac effect. Super Luminescent Diode (SLD) is a widely used light source in fiber optic gyroscope, and its characteristics will directly affect the overall performance of gyroscope. In this paper, the working mechanism of SLD light source is studied, and the photoelectric characteristics of SLD light source and the influence of light source temperature and driving current on center wavelength are analyzed. According to the relationship between the central wavelength of the light source and the driving current and die temperature, a three-dimensional model of the central wavelength of the light source is obtained. In order to control the driving current and die temperature quickly and stably, the fuzzy PID control scheme of die temperature and incremental PID control scheme of driving current are studied and designed. Based on the three-dimensional model of the center wavelength of light source, the center wavelength of SLD light source is controlled stably and quickly.

A state-space model-based temperature control system for laser remanufacturing molten pool

ABSTRACT Laser remanufacturing is a key technology for remanufacturing, which has been widely used in aerospace, metallurgy, energy and other fields. However, the problem of shape control has been the bottleneck that restricts the scale and industrial application. In the laser remanufacturing process, the molten pool temperature is the critical to determine the shape and performance stability of remanufactured parts. Based on this, the paper proposes a real-time online control method for laser remanufacturing molten pool temperature based on state space model, which solves the problem of difficult to establish control mechanism model and multiple variable constraints. Develop a real-time online control system for molten pool temperature of laser remanufacturing process based on state space model and incremental integral separation PID control, which uses a single sampling point as temperature feedback, solving the problem of lag generated by traditional feedback cycle, realizing real-time online control of molten pool temperature of laser remanufacturing process. Finally, the experimental results show that the developed molten pool temperature control system can effectively eliminate the sudden and gradual temperature change in the deposition process and significantly improve the thermal accumulation phenomenon in the deposition process, thus improving the forming quality and performance stability of remanufactured parts.

Fuzzy PID control theory in multi-objective optimal longitudinal following of intelligent trolley

Abstract As a kind of mobile robot, the intelligent trolley is also called a wheeled robot, and this field is the fastest growing in the current technological development. Smart trolleys have good automatic guidance functions, often used in modern logistics conveying systems. A fuzzy control algorithm has a good control effect for nonlinear systems and has a strong anti-interference ability. In order to optimize the multi-objective longitudinal following system of smart carts, therefore, this paper develops the study of fuzzy PID control algorithm for multi-objective longitudinal following of smart carts. Based on the incremental PID control, an improved PID algorithm is constructed by introducing incomplete differentiation, differential prior, and “optimal curvature” algorithm. Based on the actual control experience, the fuzzy control table is designed, and the adaptive control algorithm is obtained. Finally, the simulation results of the fuzzy PID control algorithm are tested by MATLAB/Simulink, and the most suitable fuzzy PID control algorithm for multi-objective optimal longitudinal following of intelligent carts is derived.

Design of 4UM-120D Electric Leafy Vegetable Harvester Cutter Height off the Ground Automatic Control System Based on Incremental PID

In this study, a 4UM-120D electric leafy vegetable harvester was employed as the research object. An automatic control system was created to maintain the cutter’s height above the ground within ±2% of the desired value. The intention was to reduce the operators’ work intensity while improving the leafy vegetable harvester’s working quality. The automatic control system for the cutter height from the ground was explained, along with its structure and operating philosophy. MATLAB was used to establish the two-phase hybrid stepper motor’s mathematical electrical equation and mechanical equation models. An analysis was carried out on the fundamentals and differences between position PID and incremental PID control algorithms. Utilizing incremental PID in combination, the control strategy for the harvester cutter height from the ground was built, and an automatic control system was produced under the corresponding control strategy. The stability, accuracy, and rapidity of the automatic control system of the cutter height from the ground under the incremental PID control strategy were analyzed by simulating different actual working conditions with MATLAB/Simulink and taking the steady-state transition time as the evaluation index. The test results show that when the deviation between the current value and the set value was greater than 2%—that is, when the harvester was in the condition of suddenly crossing the ditch or suddenly climbing the slope—the automatic control system based on the incremental PID control strategy had a good dynamic response performance and stability. This resulted in the automatic control function of the harvester cutter height off the ground being achieved. When the rotation angle PID control algorithm’s proportional coefficient is Kp = 4.665, the rotation speed PID control algorithm’s proportional coefficient is Kp = 5.65 and its integral coefficient is Ki = 3.86, and the current PID control algorithm’s proportional coefficient is Kp = 0.5455 and its integral coefficient is Ki = 30.4578. The harvester abruptly crossed a ditch while operating steadily, and the automatic control system’s steady-state transition time for the height of the cutter off the ground was 1.0811 s. The harvester abruptly climbed a slope while operating steadily, and the automatic control system’s steady-state transition time for the height of the cutter off the ground was 1.1185 s. Data from the field tests revealed a degree of reliability in the simulation test results. The study offered a strategy for raising the harvester quality for leafy vegetables while lowering the operator workload.

Coordinated Control of Unmanned Electric Formula Car

The coordinated control method of Unmanned Electric Formula Racing (UEFC) was studied to improve the handling stability of UEFC. The UEFC’s mechanical structure, which is based on the driving system and transmission system, was designed. In accordance with mechanical structure of the designed racing car, a seven-degree of freedom mathematical model of the UEFC was established. In accordance with the built mathematical model of racing car, the lateral controller of racing car was designed by using a fuzzy neural network method. The longitudinal controller of the racing car was designed by using the method of incremental PID control, and the coordination controller of the racing car was designed by combining the lateral controller and the longitudinal controller so as to realize the lateral and longitudinal coordination control of the UEFC. The experimental results showed that the output parameters such as yaw rate, vehicle speed and heading angle were slightly different from the expected output. It was confirmed that the research method can enhance the handling stability of the UEFC.

Improved fuzzy neural network control for the clamping force of Camellia fruit picking manipulator

During the operation of the vibrating mechanism, the push-shaking camellia fruit picking manipulator needs to ensure a constant force output of the clamping hydraulic motor in order to make sure that the camellia fruit tree trunk wouldn't loosen or damage, which may affect its later growth, during the picking process. In this regard, this paper derived the state space model of the valve-controlled clamping hydraulic motor system of the push-shaking camellia fruit picking manipulator, and the fuzzy wavelet neural network (FWNN) was designed on the basis of the traditional incremental PID control principle and the parameters of the neural network were optimized by the improved grey wolf optimizer (GWO). And then, the control system was simulated with the MATLAB/Simulink software without and with external interference, and compared and analyzed it with traditional PID controller and fuzzy PID (FPID) controller. The results show that the traditional PID controller and the FPID control have slow response and poor robustness, while the improved fuzzy wavelet neural network PID (IFWNN PID) controller possesses the characteristics of fast response and strong robustness, which can well meet the requirement of the constant clamping force of hydraulic motors. Finally, the field clamping test was carried out on the picking manipulator. The results show that the manipulator controlled by the IFWNN PID controller shortens the clamping time by 20.0% and reduces the clamping damage by 13.6% compared with the PID controller, which is verified that the designed controller can meet the clamping operation requirements of the camellia fruit picking machine.

The application of incremental PID control algorithm in large tuning camera

Large adjusting camera is an important facility of modern power grid, its own operation must be stable enough, but manual can not control it comprehensively, so it needs to use incremental PID control algorithm to carry out automatic control. This paper will study the application of incremental PID control algorithm in large tuning camera, mainly introduces the basic concept of PID control algorithm, and compares the incremental PID control algorithm with the position PID control algorithm, demonstrates the advantages of the incremental algorithm, and then puts forward its application method, analyzes the application effect of the incremental algorithm. Through research, the incremental PID algorithm has advantages and has more outstanding application value in the control of large adjusting camera, which can better keep the large adjusting camera in stable operation state.

Voltage and Active Power Management Control of PV Source Distributed Generations under Unbalanced Voltage of Non-islanded Microgrid

Key solution for future electrical power generation depends on alternative energy such as Solar Energy and renewable energy. Solar energy can be harvested by using a fast growing technique like Photovoltaic Plants (PV) in order to fulfill the demand of electrical energy. Proportional Integral Derivative Controller (PID controller) is added together with power electronic components such as boost converter combined with suitable controller of different maximum power point tracking techniques (MPPT) combined to optimized the PV system. In this paper, sudden irradiance and cell temperature variations are the variable input tested on grid PV systems modeled in MATLAB SIMULINK software. Incremental Conductance PID Controller with the trial and error method is used randomly in order to have good and efficient of transmission of energy and avoiding the unbalance voltage at the same time enhancing the protection system from bad disturbances. The stability of the system is checked to counter various irradiance and temperature in order to have a balance voltage and optimum energy. The new controller then been compared with previous literature in order to ensure the designed controller operating following the state of boundary and limitation of the operation.

PID Control of Permanent Magnet Synchronous Motor Based on Improved Actor-Critic Framework

Aiming at the shortcomings of the traditional PID control method that the parameters cannot be adjusted flexible, an improved Actor-Critic reinforcement learning algorithm combined with incremental PID control is proposed to improve the control performance of permanent magnet synchronous motor (PMSM). The strategy function of Actor and value function of Critic are approximated by two back propagation (BP) neural networks respectively. The simulation results show that the proposed algorithm has better control performance and effect than the traditional PID control method.

Design of DC motor controller based on MBD

This paper designs a direct current (DC) motor controller based on Arduino and Simulink to solve the problems of poor openness, complicated programming and difficult signal detection of the existing teaching experimental equipment. The controller integrates the Model-Based Design (MBD) concept, involving single-chip microcomputer, system modeling, micromotor, automatic control and other technologies. The hardware system includes Arduino, encoder, driver, input/output and other interfaces. The software system uses Simulink as the software development platform of the experimental device. It has the functions of algorithm design, simulation, execution, real-time data observation, etc. The limiting incremental PID control algorithm is used to control the speed of the DC motor, and the experimental results verify the design requirements. The hardware and software systems have the characteristics of good openness, fast implementation, safe and reliable, low cost, can complete the verification and improvement of various algorithms such as motor control, and can meet the teaching and research needs of the training of new engineering and technology.

A self‐adaptive SAC‐PID control approach based on reinforcement learning for mobile robots

AbstractProportional–integral–derivative (PID) control is the most widely used in industrial control, robot control, and other fields. However, traditional PID control is not competent when the system cannot be accurately modeled and the operating environment is variable in real time. To tackle these problems, we propose a self‐adaptive model‐free SAC‐PID control approach based on reinforcement learning for automatic control of mobile robots. A new hierarchical structure is developed, which includes the upper controller based on soft actor‐critic (SAC), one of the most competitive continuous control algorithms, and the lower controller based on incremental PID controller. SAC receives the dynamic information of the mobile robot as input and simultaneously outputs the optimal parameters of incremental PID controllers to compensate for the error between the path and the mobile robot in real time. In addition, the combination of 24‐neighborhood method and polynomial fitting is developed to improve the adaptability of SAC‐PID control method to complex environment. The effectiveness of the SAC‐PID control method is verified with several different difficulty paths both on Gazebo and real mecanum mobile robot. Furthermore, compared with fuzzy PID control, the SAC‐PID method has merits of strong robustness, generalization, and real‐time performance.

A variable-voltage ultra-capacitor/battery hybrid power source for extended range electric vehicle

Energy storage system of extended-range electric vehicle faces great challenges in working efficiency and energy utilization to meet the requirement of various working conditions of vehicle, efficient ultra-capacitor/battery hybrid power source is an effective way to tackle these challenges. This paper takes an ultra-capacitor/battery hybrid power source based on series-parallel switchover technology of ultra-capacitors as the research object, launches a fundamental study on its operation principle, control method and simulation/experimental verification. A significative series-parallel switchover technology of ultra-capacitors is adopted to achieve variable-voltage output of the hybrid power source, which overcomes the technical limitation of the existing hybrid power source with only a fixed working voltage output, enables the voltage-conversion ratio of the power converter to be controlled in a highly efficient range. The bi-directional four working modes of the hybrid power source that can fit the various working conditions of vehicle are analyzed. Following this, an incremental digital PID controller suitable for this energy storage system is presented. After that, a comprehensive comparison and analysis of the simulation and small-power experiment based on the simulated working conditions of vehicle are performed. The results have verified the feasibility and effectiveness of the proposed hybrid power source and its control method.

Design of temperature control system for infant radiant warmer based on Kalman filter-fuzzy PID

In order to improve the dynamic and static performance of the temperature control system of the baby radiant warmer, a Kalman filter-fuzzy PID (KFPID)algorithm is proposed on the basis of the ordinary incremental PID control algorithm. The system uses STM32 as the main controller. The temperature data is collected by the TLV2548 analog-to-digital conversion chip, and the feedback data is filtered by Kalman filter, and the bed surface of the warming table is controlled by the fuzzy PID control algorithm. After the simulation of Matlab, it can be seen that compared with the traditional PID temperature control algorithm, the KFPID algorithm has the characteristics of short adjustment time and almost zero overshoot, and the steady-state error is smaller when dealing with the same interference noise.

Development of TREND dynamics code for molten salt reactors

The Molten Salt Reactor (MSR), one of the six advanced reactor types of the 4th generation nuclear energy systems, has many impressive features including economic advantages, inherent safety and nuclear non-proliferation. This paper introduces a system analysis code named TREND, which is developed and used for the steady and transient simulation of MSRs. The TREND code calculates the distributions of pressure, velocity and temperature of single-phase flows by solving the conservation equations of mass, momentum and energy, along with a fluid state equation. Heat structures coupled with the fluid dynamics model is sufficient to meet the demands of modeling MSR system-level thermal-hydraulics. The core power is based on the point reactor neutron kinetics model calculated by the typical Runge-Kutta method. An incremental PID controller is inserted to adjust the operation behaviors. The verification and validation of the TREND code have been carried out in two aspects: detailed code-to-code comparison with established thermal-hydraulic system codes such as RELAP5, and validation with the experimental data from MSRE and the CIET facility (the University of California, Berkeley’s Compact Integral Effects Test facility).The results indicate that TREND can be used in analyzing the transient behaviors of MSRs and will be improved by validating with more experimental results with the support of SINAP.

Adaptive Authority Allocation of Human-Automation Shared Control for Autonomous Vehicle

Great advances had been achieved in the discipline of environmental perception, motion planning and control strategy implementation, however, fully autonomous vehicle is still far from large-scale commercial application. The concept of “human-automation shared control” provides a promising solution to enhance autonomous driving safety, to which great research effort has been contributed in recent years. Nevertheless, more attention should be given to the following aspects. The present shared control strategy either only considers the discontinuous switching control between driver and ADS or investigates the simple effect of driver’s behavior in specific scenarios. The adaptive authority allocation between the driver’s active assistance and ADS hasn’t been investigated yet. In this paper, a shared control experiment with driver’s active assistance is conducted in scheduled traffic scenarios to observe the state of vehicle and arm’ EMG signal. After that, we construct a feature classification algorithm for shared control authority by clustering the experimental data. Then, a SCS with incremental PID controller and 2 DOF vehicle dynamic model is proposed. For validation of the SCS, the comparison of vehicle performance for different control authority illustrates that SCS can allocate appropriate control authority to improve the safety.