Control of a Direct-Drive Arm

A direct-drive arm is a mechanical arm in which the shafts of articulated joints are directly coupled to the rotors of motors with high torque. Since the arm does not contain transmission mechanisms between the motors and their loads, the drive system has no backlash, small friction, and high mechanical stiffness, all of which are desirable for fast, accurate, and versatile robots. First, the prototype robot is described, and basic feedback controllers for single-link drive systems are designed. Second, feedforward compensation is discussed. This compensation significantly reduces the effect of interactions among multiple joints and nonlinear forces. The experiments showed the excellent performance of the direct-drive arm in terms of speed and accuracy.

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A Review of Transverse Flux Machines Topologies and Design

Energies ◽

10.3390/en14217173 ◽

2021 ◽

Vol 14 (21) ◽

pp. 7173

Author(s):

Víctor Ballestín-Bernad ◽

Jesús Sergio Artal-Sevil ◽

José Antonio Domínguez-Navarro

Keyword(s):

Power Systems ◽

Prime Mover ◽

Variable Speed ◽

Direct Drive ◽

Comprehensive Review ◽

Potential Applications ◽

High Torque ◽

Transverse Flux ◽

Drive Systems ◽

Load Variable

High torque and power density are unique merits of transverse flux machines (TFMs). TFMs are particularly suitable for use in direct-drive systems, that is, those power systems with no gearbox between the electric machine and the prime mover or load. Variable speed wind turbines and in-wheel traction seem to be great-potential applications for TFMs. Nevertheless, the cogging torque, efficiency, power factor and manufacturing of TFMs should still be improved. In this paper, a comprehensive review of TFMs topologies and design is made, dealing with TFM applications, topologies, operation, design and modeling.

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Analysis of Torque Ripples of an Induction Motor Taking into Account a Inter-Turn Short-Circuit in a Stator Winding

Energies ◽

10.3390/en13143626 ◽

2020 ◽

Vol 13 (14) ◽

pp. 3626 ◽

Cited By ~ 1

Author(s):

Wojciech Pietrowski ◽

Konrad Górny

Keyword(s):

Early Stage ◽

Short Circuit ◽

Torque Ripple ◽

Drive System ◽

Electrical Machines ◽

Stator Winding ◽

Permanent Magnet Synchronous Machines ◽

Noninvasive Diagnostics ◽

Drive Systems ◽

Commercial Applications

Despite the increasing popularity of permanent magnet synchronous machines, induction motors (IM) are still the most frequently used electrical machines in commercial applications. Ensuring a failure-free operation of IM motivates research aimed at the development of effective methods of monitoring and diagnostic of electrical machines. The presented paper deals with diagnostics of an IM with failure of an inter-turn short-circuit in a stator winding. As this type of failure commonly does not lead immediately to exclusion of a drive system, an early stage diagnosis of inter-turn short-circuit enables preventive maintenance and reduce the costs of a whole drive system failure. In the proposed approach, the early diagnostics of IM with the inter-turn short-circuit is based on the analysis of an electromagnetic torque waveform. The research is based on an elaborated numerical field–circuit model of IM. In the presented model, the inter-turn short-circuit in the selected winding has been accounted for. As the short-circuit between the turns can occur in different locations in coils of winding, computations were carried out for various quantity of shorted turns in the winding. The performed analysis of impact of inter-turn short-circuit on torque waveforms allowed to find the correlation between the quantity of shorted turns and torque ripple level. This correlation can be used as input into the first layer of an artificial neural network in early and noninvasive diagnostics of drive systems.

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Mechanical-Level Hardware-In-The-Loop and Simulation in Validation Testing of Prototype Tower Crane Drives

Energies ◽

10.3390/en13215727 ◽

2020 ◽

Vol 13 (21) ◽

pp. 5727

Author(s):

Michał Michna ◽

Filip Kutt ◽

Łukasz Sienkiewicz ◽

Roland Ryndzionek ◽

Grzegorz Kostro ◽

...

Keyword(s):

Laboratory Testing ◽

Environmental Parameters ◽

Experimental Tests ◽

Drive System ◽

Hardware In The Loop ◽

Dynamic Simulations ◽

Tower Crane ◽

University Of Technology ◽

New Type ◽

Drive Systems

In this paper, the static and dynamic simulations, and mechanical-level Hardware-In-the-Loop (MHIL) laboratory testing methodology of prototype drive systems with energy-saving permanent-magnet electric motors, intended for use in modern construction cranes is proposed and described. This research was aimed at designing and constructing a new type of tower crane by Krupiński Cranes Company. The described research stage was necessary for validation of the selection of the drive system elements and confirmation of its compliance with applicable standards. The mechanical construction of the crane was not completed and unavailable at the time of testing. A verification of drive system parameters had to be performed in MHIL laboratory testing, in which it would be possible to simulate torque acting on the motor shaft. It was shown that the HIL simulation for a crane may be accurate and an effective approach in the development phase. The experimental tests of selected operating cycles of prototype crane drives were carried out. Experimental research was performed in the LINTE^2 laboratory of the Gdańsk University of Technology (Poland), where the MHIL simulator was developed. The most important component of the system was the dynamometer and its control system. Specialized software to control the dynamometer and to emulate the load subjected to the crane was developed. A series of tests related to electric motor environmental parameters was carried out.

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Novel switched reluctance servo direct-drive system

IEEE International Conference Mechatronics and Automation, 2005 ◽

10.1109/icma.2005.1626598 ◽

2006 ◽

Cited By ~ 3

Author(s):

Hao Chen ◽

Fengfeng Zhuang

Keyword(s):

Drive System ◽

Direct Drive ◽

Switched Reluctance

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Optimized design of inner potential waveform of PMSM for low-speed & high-torque drive systems

Proceedings. International Conference on Power System Technology ◽

10.1109/icpst.2002.1047593 ◽

2003 ◽

Cited By ~ 4

Author(s):

Zhang Bingyi ◽

Feng Guihong ◽

Wang Fengxiang ◽

Wang Yiquan ◽

Wang Lifeng ◽

...

Keyword(s):

Optimized Design ◽

Low Speed ◽

High Torque ◽

Drive Systems ◽

Potential Waveform

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Comparative Analysis of the Control Rod Drive System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.614-615.1558 ◽

2012 ◽

Vol 614-615 ◽

pp. 1558-1561

Author(s):

Wen Wei Han ◽

Wei Shi Han ◽

Qing Guo

Keyword(s):

Comparative Analysis ◽

Drive System ◽

Hydraulic Control ◽

Control Rod ◽

Rod System ◽

Drive Systems ◽

Research Situation

This article has systematically summarized the recent research situation of control rod system in China and comparatively analyzed the features of a variety of control rod drive systems on a basis of brief introduction of common types of control rod drive system. It has been proposed to that the hydraulic control rod drive system have a great potential in a wide application concerning on ships, warships power reactors and protable desalination system.

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Design and Optimization of a High-Torque-Density Low-Torque-Ripple Vernier Machine Using Ferrite Magnets for Direct-Drive Applications

IEEE Transactions on Industrial Electronics ◽

10.1109/tie.2021.3090714 ◽

2021 ◽

pp. 1-1

Author(s):

Cheng Gong ◽

Fang Deng

Keyword(s):

Torque Ripple ◽

Direct Drive ◽

Torque Density ◽

Design And Optimization ◽

High Torque ◽

Low Torque

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High-Cycle Fatigue of Shafts due to Starting Transients in Drive Systems

Proceedings of the Institution of Mechanical Engineers Part D Transport Engineering ◽

10.1243/pime_proc_1988_202_174_02 ◽

1988 ◽

Vol 202 (3) ◽

pp. 201-209 ◽

Cited By ~ 1

Author(s):

S G Velonias ◽

N A Aspragathos

Keyword(s):

Structural Characteristics ◽

Drive System ◽

Suggested Approach ◽

Loss Of Life ◽

Speed Reducer ◽

Starting Conditions ◽

General Drive ◽

Drive Systems ◽

Non Linear System ◽

Spring Constants

This paper investigates some of the effects that structural characteristics and main non-linearities of a drive system have on systems response and its shaft fatigue. In the suggested approach a general drive system, including a motor, load and speed reducers, is modelled as a multi-degree-of-freedom torsional vibrations non-linear system. The differential equations of the system are formed automatically. The user of the developed program must input just the constants of the components. An algorithm to compute the loss of life of the shafts due to fatigue is also incorporated into the program. As an example, a drive system, including a motor, a speed reducer and load is modelled and tested under starting conditions. The effects of changing spring constants of the shafts and the backlash of the speed reducer are investigated.

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