The Effects of Permanent Magnet Segmentations on Electromagnetic Performance in Ironless Brushless DC Motors

This paper investigates the electromagnetic torque by considering back electromagnetic force (back-EMF) trapezoidal degrees of ironless brushless DC (BLDC) motors through the two-dimensional finite element method (2-D FEM). First, the change percentages of the electromagnetic torque with back-EMF trapezoidal degrees, relative to those of PMs without segments, are investigated on the premise of the same back-EMF amplitude. It is found that both PM symmetrically and asymmetrically segmented types influence back-EMF trapezoidal degrees. Second, the corresponding electromagnetic torque, relative to that of PMs without segments, is studied in detail. The results show that the electromagnetic torque can be improved or deteriorated depending on whether the back-EMF trapezoidal degree is lower or higher than that of PMs without segments. Additionally, the electromagnetic torque can easily be improved by increasing the number of PMs’ symmetrical segments. In addition, the electromagnetic torque in PMs with asymmetrical segments is always higher than that of PMs without segments. Finally, two ironless PM BLDC motors with PMs symmetrically segmented into three segments and without segments are manufactured and tested. The experimental results show good agreement with those of the 2-D FEM method. This approach provides significant guidelines to electromagnetic torque improvement without much increase in manufacturing costs and process complexity.

Practical Tracking Control Under Actuator Saturation for a Class of Flexible-Joint Robotic Manipulators Driven by DC Motors

This paper is devoted to the practical tracking control for a class of flexible-joint robotic manipulators driven by DC motors. Different from the related literature where control constraint is neglected and the disturbances are excluded or only exist in one subsystem, actuator saturation is considered in this paper while the disturbances are present in all the three subsystems. This leads to the incapability of the traditional schemes on this topic. For this, a novel control design scheme is proposed by skillfully incorporating adaptive dynamic compensation technique, constructive methods of command filters and an auxiliary system for the actuator saturation into the backstepping framework, and in turn to design a practical tracking controller which ensures that all the states of the resulting closed-loop system are bounded and the system output practically tracks the reference signal. It is worthwhile strengthening that a more wider class of reference signals can be tracked since they are only first order continuously differentiable but twice or more in the related literature. Finally, a numerical example is provided to validate the effectiveness of the proposed theoretical results.

Negotiating Uneven Terrain by a Simple Teleoperated Tracked Vehicle with Internally Movable Center of Gravity

We propose a mechanical design for a simple teleoperated unmanned ground vehicle (UGV) to negotiate uneven terrain. UGVs are typically classified into legged, legged-wheeled, wheeled, and tanked forms. Legged vehicles can significantly shift their center of gravity (COG) by positioning their multi-articulated legs at appropriate trajectories, stepping over a high obstacle. To realize a COG movable mechanism with a small number of joints, a number of UGVs have been developed that can shift their COG by moving a mass at a high position above the body. However, these tend to pose a risk of overturning, and the mass must be moved quite far to climb a high step. To address these issues, we design a novel COG shift mechanism, in which the COG can be shifted forward and backward inside the body by moving most of its internal devices. Since this movable mass includes DC motors for driving both tracks, we can extend the range of the COG movement. We demonstrate that a conventional tracked vehicle prototype can traverse a step and a gap between two steps, as well as climb stairs and a steep slope, with a human operating the vehicle movement and the movable mass position.

Industrial Crane Automation Using Cloud with Artificial Intelligent and Machine Learning

This paper describes the design and development of a construction crane for use in lifting in the heavy weight object at construction site. The construction crane was developed by automatic system which was modified by adding the sensors like proxy sensors, pressure sensors and advance control system. The crane using 3 phase dc motors and voltage range of 220 to 650 volts. The cranes system is controlled through android app using an internet implementing adequate algorithms to ensure a smooth movement and prevent the undesired swinging effects. The machine is operated via a Man Machine Interface (MMI) installed in the android mobile. The range of crane control operations extended by using the internet of things (IOT).

Control of vibrational field in an elastic vibration unit with DC motors and time-varying observer

In the paper the problem of feedback control of vibrational fields in a vibration unit is analyzed taking into account the influence of the elasticity of cardan shafts, the drive dynamics, saturation for control torques. In addition, the synthesized rotor synchronization control algorithm uses the estimates of a non-stationary observer, which makes it possible to implement it practically on a two-rotor vibration unit SV-2. The performance of the closed loop mechatronic systems is examined by simulation for the model of the two-rotor vibration unit SV-2.

Low-Cost Drive System for Electric Motors based on the IRAM Module

With the increasing use of equipment that demand electric drive systems, the need for new systems that meet requirements of compactness, versatility, safety and low cost has increased. The IRAM module is an electronic circuit that provides a driver for DC and AC motors, being extremely compact and presents high performance. In this context, this work contributes to the power electronics area, presenting a design and construction of a low cost drive system, based on IRAM module, developed for individual or simultaneous drive, up to two DC motors. To carry out the experiments, DC motors responsible for moving a welding robot, were used. Experimental results are presented to shown the feasibility of using this system.

Sliding Mode Control for a DC Motor System with Dead-Zone

Due to the simple structure of DC motors, the natural decoupling between torque and speed, and its low cost the DC motors have been widely used in electromechanical systems, the paper deals with the experimental method of DC motor Coulomb friction identification that caused the dead nonlinear zone and proposed a nonlinear model of the DC motor, then a sliding mode strategy is developed to control the DC motor in high and low speed for bidirectional operation, The experimental implementation using Dspace 1104 demonstrate that the proposed sliding mode control can achieve favorable tracking performance against non-linearities for a DC motor.

Battery Power Control and Monitoring System with Internet of Things Technology

Along with the development of battery/ACCU technology, the ACCU charging and loading system has also developed manually or automatically. In this paper, the results of research on the manufacture of tools that function to monitor and control the charging and loading of electrical power will be explained from batteries that are burdened with lights and DC motors through a control panel or android smart phone with IoT technology. This tool is designed to monitor 2 ACCUs, namely ACCU1 and ACCU2. ACCU1 is loaded with lamp and parallel with DC motor load while ACCU2 is loaded with DC motor and parallel with lamp load. If ACCU1 and ACCU2 are full, ACCU1 is loaded with only one lamp and ACCU2 is only loaded with DC motor. For example, ACCU1's electrical power is still within the limits that can be loaded with lights and DC motors while ACCU2 can't be loaded because electric power is not capable of being loaded with DC motors, the DC motor's load will be transferred to ACCU1. So that ACCU1 is loaded with DC lamps and motors and ACCU2 is charging the electricity, as well as for the opposite condition. The design of this tool uses the main component of the ESP32 microcontroller, where this component has been integrated with the wifi module and other supporting circuit modules, namely the current sensor circuit, voltage sensor and OLED display. The software design consists of a program code designer for hardware using C++ and an android smart phone application design using MIT App Inventor. The results of this study are in accordance with the design specifications, namely the device can be used to control charging and loading as well as monitor ACCU1 and ACCU2 electrical power on OLED screens and on Android smart phones screens

Comparative research of electrical energy transformation processes in locomotive traction drives with asynchronous motors and series-wound brushed DC motors

An estimate of the Russian railways expenses level for the purchase of fuel and energy resources is given. It is shown the costs for the purchase of electric energy for train traction account for more than half of the total costs. In this regard, the problem of increasing the traction rolling stock energy efficiency seems certainly relevant. The diagram of voltage and current measurements at the primary winding of the AC cargo electric locomotive transformer is given. The experimental data processing algorithm is proposed. A comparative analysis of the results obtained for electric locomotives with series-wound brushed DC motors (throughout what follows will be denoted as BTMs) and asynchronous traction motors (will be denoted as ATMs) showed that the power factor of the asynchronous drive is higher: 0.99, compared to 0.65 for the drive with BTMs; and the coefficient of nonlinear current distortions is only 0.15, compared to 0.53 for the BTMs. The conclusion is made about higher efficiency of electric energy conversion process in asynchronous traction drive in trust mode.