Robust Speed Control of a Three Phase Induction Motor Using Support Vector Regression

The Three Phase Induction Motor (TIM) is one of the most widely used motors due to its low price, robustness, low maintenance cost, and high efficiency. In this paper, a Support Vector Regression (SVR) based controller for TIM speed control using Indirect Vector Control (IVC) is presented. The IVC method is more frequently used because it enables better speed control of the TIM with higher dynamic performance. Artificial Neural Network (ANN) controllers have been widely used for TIM speed control for several reasons such as their ability to successfully train without prior knowledge of the mathematical model, their learning ability, and their fast implementation speed. The SVR-based controller overcomes the drawbacks of the ANN-based controller, i.e. its low accuracy, overfitting, and poor generalization ability. The speed response under the proposed controller is faster in terms of rising and settling time. The dynamic speed response of the proposed controller is also superior to that of the ANN-PI controller. The performance of the proposed controller was compared for TIM speed control with an ANN-PI controller via simulations in SIMULINK.

Effect of Baseline BMI and IL-6 on Gait Speed Response to Caloric Restriction in Older Adults

We examined whether the effect of caloric restriction (CR) on gait speed change in older adults (67.3±5.27 years) varied by BMI and interleukin 6 (IL-6). Data from eight six-month randomized controlled trials were pooled, with 1268 participants randomized to CR (n=710) and non-CR (n=558) conditions. Baseline BMI/IL-6 subgroups were constructed using BMI≥35 kg/m2 and IL-6>2.5 pg/dL, and participants were jointly classified as high/high (n=395), high/low (n=208), low/high (n=271), or low/low (n=344). Overall treatment effects showed significant improvements in gait speed in CR versus non-CR [mean difference: 0.02 m/s (95% CI: 0.01, 0.04)]; however, CR assignment significantly interacted with BMI/IL-6 subgroup (p=0.03). Greatest gait speed improvement was observed in the high/high CR subgroup [+0.06 m/s (0.03, 0.09)] and appeared to be driven by no gait speed change among the high/high non-CR subgroup. Gait speed response to CR was greatest in older adults with elevated baseline BMI and IL-6.

A High-Speed Current Source for Magnetorheological Application

Current source is an indispensable component of magnetorheological (MR) systems. Though MR fluid has a phase change as fast as in 1 ms, the response of MR damper (MRD) to generate the damping force may be two orders of magnitude longer. Therefore, the rapid response of current source is a key to realize the real-time semi-active control of MR devices. This study proposes a programmable high-speed, low-cost current source exclusively for MR devices based on the synergy between supercapacitor and Buck converter (i.e., SSBC current source). SSBC current source features a strategy consisting of a lifting phase of supercapacitor and a following maintaining phase of Buck converter. Specifically, the high power density of supercapacitor contributes to rapidly lifting/raising the initial current, and then, like a “relay race”, the expected output is maintained through a Buck converter. Theoretical modeling and experiments are performed systematically. The response times (@ 95% of expected outputs) measured are 0.44, 0.84 and 1.88 ms for the outputs of 3, 6 and 9 A, respectively; these values are highlighted as the fastest level in this field. Besides, the response can be up to 24.6 and 43.7 times faster than the cases using supercapacitor and Buck converter to directly drive the MRD, respectively. SSBC current source is employed to generate a sequence of currents/magnetic inductions, only four variables of which need to be controlled programmatically: the order of lifting and maintaining phases, switching time of lifting phase, PWM duty cycle of Buck converter and duration of maintaining phase. The response time stability is verified by 100 cycles of on/off tests, showing a fluctuation of only 1.1%, which indicates a very reliable high-speed response. This study provides an exclusive power supply with a novel strategy for MR devices, which is believed to be an important promotion for MR technologies.

Performance and Analysis of Indirect Torque Control-Based Three-Phase Induction Motor

Induction motors are widely used in industrial processes, vehicles and automation. Three-phase induction motors can be used for traction systems on electric locomotives. In this case, the speed control system is an important thing that must be applied to the propulsion system. This study aimed to test the indirect torque control for a Three-phase induction motor. A proportional integral (PI) controller was applied for speed controller. The indirect torque control system was modeled and simulated using PSIM software. According to the result, the control method showed a good performance. The speed could be maintained even the speed reference was changing or a load was applied. The steady state error of the speed response was just 0.1% with rise time around 0.06 s. The stator current went up to 39.5 A in starting condition. The stator current reached 12 A rms when the load of 10 Nm was applied. Then, the current rose to 15.7 A rms when the load was increased to 40 Nm and the current came down to 12.8 A rms when the load was decreased to 20 Nm.

MATLAB based design and performance analysis of electronically commutated BLDC motor

The main objective of this research work is to design the electronically communtated brushless direct current (BLDC) motor and analysis its performance in MATLAB environment. The use of BLDC engine is expanding daily, the performance analysis is progressively significant and the consumer loyalty is significant. In light of the ranking and requirements, the BLDC engine is planned. The BLDC motor is widely used in a variety of fields. Low ripple input supply and a suitable speed controller are needed to achieve desired motor output. The output of BLDC motors, such as torque, voltage, and speed response, is examined in this paper. The controller parameters have been fine-tuned to improve motor speed. It has been discovered that a three phase voltage source inverter (VSI) fed BLDC motor with a fractional-order proportional-integral-derivative (FOPID) controller provides superior BLDC motor response. The outcomes are broke down utilizing the MATLAB programming.

Enhancement in pneumatic positioning system using nonlinear gain constrained model predictive controller: experimental validation

The issues of inaccurate positioning control have made an industrial use of pneumatic actuator remains restricted to certain applications only. Non-compliance with system limits and properly control the operating system may also degrade the performance of pneumatic positioning systems. This study proposed a new approach to enhance pneumatic positioning system while considering the constraints of system. Firstly, a mathematical model that represented the pneumatic system was determined by system identification approach. Secondly, model predictive controller (MPC) was developed as a primary controller to control the pneumatic positioning system, which took into account the constraints of the system. Next, to enhance the performance of the overall system, nonlinear gain function was incorporated within the MPC algorithm. Finally, the performances were compared with other control methods such as constrained MPC (CMPC), proportional-integral (PI), and predictive functional control with observer (PFC-O). The validation based on real-time experimental results for 100 mm positioning control revealed that the incorporation of nonlinear gain within the MPC algorithm improved 21.03% and 2.69% of the speed response given by CMPC and PFC-O, and reduced 100% of the overshoot given by CMPC and PI controller; thus, providing fast and accurate pneumatic positioning control system.

Pharmaceutical supply chains and management innovation?

Purpose This paper aims to evaluate the implementation of innovative programmes within the downstream domain of the pharmaceutical supply chain (PSC), with the aim of informing improved service provision. Design/methodology/approach A mixed-method approach was used to assess to what extent innovation could be adopted by hospital and community pharmacies to improve the delivery process of pharmaceutical products. Unstructured interviews and 130 questionnaires were collected and analysed to identify factors that facilitate or prevent innovation within PSC processes. Findings The analysis led to the creation of the innovative pharmaceutical supply chain framework (IPSCF) that provides guidance to health-care organisations about how supply chain management problems could be addressed by implementing innovative approaches. The results also indicated that the implementation of Lean and Reverse Logistics (RL) practices, supported by integrated information technology systems, can help health-care organisations to enhance their delivery in terms of quality (products and service quality), visibility (knowledge and information sharing), speed (response to customers and suppliers needs) and cost (minimisation of cost and waste). Practical implications The study’s recommendations have potential implications for supply chain theory and practice, particularly for pharmacies in terms of innovation adoption. The IPSCF provides guidance to pharmacies and health-care organisations to develop more efficient and effective supply chain strategies. Originality/value This research contributes to the academic literature as it adds novel theoretical insights to highly complex delivery process innovation.

Design of speed control system for intelligent sorting conveyor belt of coal gangue

With the development of technology, the application of intelligent coal gangue sorting is more and more favored by coal mining enterprises. The coal gangue intelligent sorting system has higher requirements on the coal conveyor belt. The traditional transmission system has the problems of slow speed response, unstable operation, high energy consumption and jitter in the process of speed change. Using PLC, touch screen, frequency converter, RS-485, sensors and so on, the speed control and speed monitoring system of belt transport mechanism is constructed. By analyzing the error law of the system speed control and using Numpy system analysis and calculation, speed pre-compensation can be made. Then by controling speed precision through the PID and monitoring display through the time-speed curve, the real-time automation gives an alarm for abnormal speed situation. According to the speed requirement of the intelligent sorting system of coal gangue, the system can quickly reach the predetermined speed value, and effectively eliminate the shaking phenomenon in the process of changing speed. The system has strong universality, easy maintenance, and stable speed control, which is conducive to improving the reliability and efficiency of the intelligent sorting system for coal gangue and reduceing transmission mechanism wear caused by dithering.