Frequency and time domain characteristics of digital control of electric vehicle in-wheel drives

Abstract In-wheel electric drives are promising as actuators in active safety systems of electric and hybrid vehicles. This new function requires dedicated control algorithms, making it essential to deliver models that reflect better the wheel-torque control dynamics of electric drives. The timing of digital control events, whose importance is stressed in current research, still lacks an analytical description allowing for modeling its influence on control system dynamics. In this paper, authors investigate and compare approaches to the analog and discrete analytical modeling of torque control loop in digitally controlled electric drive. Five different analytical models of stator current torque component control are compared to judge their accuracy in representing drive control dynamics related to the timing of digital control events. The Bode characteristics and stepresponse characteristics of the analytical models are then compared with those of a reference model for three commonly used cases of motor discrete control schemes. Finally, the applicability of the presented models is discussed.

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An optimal wheel-torque control on a compliant modular robot for wheel-slip minimization

Robotica ◽

10.1017/s0263574715000685 ◽

2015 ◽

Vol 35 (2) ◽

pp. 463-482 ◽

Cited By ~ 5

Author(s):

Avinash Siravuru ◽

Suril V. Shah ◽

K. Madhava Krishna

Keyword(s):

Friction Coefficient ◽

Normal Force ◽

Experimental Studies ◽

Traction Force ◽

Static Stability ◽

Wheel Speed ◽

Torque Control ◽

Modular Robot ◽

Wheel Slip ◽

Wheel Torque

SUMMARYThis paper discusses the development of an optimal wheel-torque controller for a compliant modular robot. The wheel actuators are the only actively controllable elements in this robot. For this type of robots, wheel-slip could offer a lot of hindrance while traversing on uneven terrains. Therefore, an effective wheel-torque controller is desired that will also improve the wheel-odometry and minimize power consumption. In this work, an optimal wheel-torque controller is proposed that minimizes the traction-to-normal force ratios of all the wheels at every instant of its motion. This ensures that, at every wheel, the least traction force per unit normal force is applied to maintain static stability and desired wheel speed. The lower this is, in comparison to the actual friction coefficient of the wheel-ground interface, the more margin of slip-free motion the robot can have. This formalism best exploits the redundancy offered by a modularly designed robot. This is the key novelty of this work. Extensive numerical and experimental studies were carried out to validate this controller. The robot was tested on four different surfaces and we report an overall average slip reduction of 44% and mean wheel-torque reduction by 16%.

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Additive boundary of error probability in a discrete data transmission channel with noise-immune coding and grouping of errors

Information and Control Systems ◽

10.31799/1684-8853-2020-4-78-86 ◽

2020 ◽

pp. 78-86

Author(s):

Valentin Dzhumkov ◽

Georgy Maltsev

Keyword(s):

Data Transmission ◽

Error Probability ◽

Theory Development ◽

Analytical Description ◽

Discrete Data ◽

Analytical Models ◽

Binomial Model ◽

Transmission Channel ◽

Bit Error Probability ◽

Analytical Expressions

Introduction: Data transmission reliability analysis when using noise-immune coding in channels with grouping of errors (in particular, in radio channels with interference and fading of the received signals) is complicated by the need to use discrete data transmission channel models which take into account the error grouping, differing from the traditional binomial model. The complexity of the analytical description of such models leads to the fact that the quality indicators of data transmission over channels with error grouping are usually analyzed by simulation methods, and the development of analytical models of data transmission discrete channels with grouping of errors is one of the modern direction in the noise-immune coding theory development. Purpose: Finding the additive boundary of a bit error probability for data transmission discrete channel with grouping of symbol errors, described by Elliot — Hilbert model. Results: For the case of data transmission using a group noise-immune code, analytical expressions are obtained for calculating the additive boundary of a bit error probability in a discrete data transmission channel with grouping of symbol errors. The obtained expressions take into account the features of data transmission over a channel with error grouping, in particular, the fact that the probabilities of various combinations of the same number of errors are not equal to each other. Examples are presented of calculating a bit error probability for the case of using noise-immune codes which correct errors. It is shown that for any code length, the use of the Elliot — Hilbert model allows you to substantially refine the results of calculating the probabilistic indicators of the reliability of data transmission in channels with error grouping, as compared to the original binomial model. The obtained results are compared to the results of the simulation. Practical relevance: The results can be used in the design and analysis of the characteristics of data transmission systems for various purposes, operating under conditions of error grouping. Using analytical expressions to calculate the probability indicators of the reliability of data transfer allows you to abandon complex simulation modeling of transmitting data in channels with error grouping at the stage of choosing a noise-immune code and its parameters.

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Digital Control of Electric Drives

10.1016/c2009-0-08991-0 ◽

1992 ◽

Keyword(s):

Digital Control ◽

Electric Drives

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Bistable composite helices with thermal effects

Proceedings of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rspa.2019.0295 ◽

2019 ◽

Vol 475 (2229) ◽

pp. 20190295 ◽

Cited By ~ 2

Author(s):

Seán Carey ◽

Robert Telford ◽

Vincenzo Oliveri ◽

Ciaran McHale ◽

Paul Weaver

Keyword(s):

Thermal Effects ◽

Design Space ◽

Analytical Description ◽

Analytical Models ◽

Fatigue Properties ◽

Finite Element Models ◽

Helical Structures ◽

Industrial Sectors ◽

Strength And Stiffness ◽

Increased Strength

Morphing technologies use large, seamless changes in the shape of a structure to enable multi-functionality and reconfigurability. Several industrial sectors could benefit from morphing structures, including medical, energy and aerospace which require lightweight, simple and reliable solutions. Composite materials are key to lightweight morphing technologies due to their increased strength- and stiffness-to-mass ratios, stiffness tailorability and excellent fatigue properties, all of which reduce the mass and complexity of these types of structures. By accounting for thermal effects in their analytical description, we enhance the viability of multi-stable composite helical structures. This consideration improves predictions of existing analytical models in comparison with experiments, while also vastly expanding the design space to include antisymmetric and non-symmetric flange lay-up sequences. The developed analytical model is presented and verified using both finite-element models and experiments. By including thermal effects, we show that beneficial new morphing behaviours can be obtained.

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Disturbance adaptive steering wheel torque control for enhanced path tracking of autonomous vehicles

2017 American Control Conference (ACC) ◽

10.23919/acc.2017.7963299 ◽

2017 ◽

Cited By ~ 1

Author(s):

Dongpil Lee ◽

Kyongsu Yi

Keyword(s):

Autonomous Vehicles ◽

Path Tracking ◽

Torque Control ◽

Steering Wheel ◽

Wheel Torque

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Inverse Wheel Dynamics

Dynamic Systems and Control, Parts A and B ◽

10.1115/imece2006-13787 ◽

2006 ◽

Cited By ~ 5

Author(s):

V. V. Vantsevich

Keyword(s):

Angular Velocity ◽

Power Distribution ◽

Vehicle Dynamics ◽

Inverse Dynamics ◽

Equation Of Motion ◽

Torque Control ◽

Vehicle Performance ◽

Performance Control ◽

Wheel Torque ◽

And Performance

Wheel dynamics is a significant component of vehicle dynamics and performance analysis. This paper presents an innovative method of studying wheel dynamics and wheel performance control based on the inverse dynamics formulation of the problem. Such an approach opens up a new way to the optimization and control of both vehicle dynamics and vehicle performance by optimizing and controlling power distribution to the drive wheels. An equation of motion of a wheel is derived first from the wheel power balance equation that makes the equation more general. This equation of motion is considered the basis for studying both direct and inverse wheel dynamics. The development of a control strategy on the basis of the inverse wheel dynamics approach includes wheel torque control that provides a wheel with both the referred angular velocity and rolling radius and also with the required functionals of quality. An algorithm for controlling the angular velocity is presented as the first part in the implementation of the developed strategy of the inverse wheel dynamics/performance control.

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Optimal digital control of an uncertain parameter 2nd order plant

Science Technology and Innovation ◽

10.5604/01.3001.0012.0889 ◽

2018 ◽

Vol 2 (1) ◽

pp. 59-63

Author(s):

Krzysztof Oprzędkiewicz

Keyword(s):

Control System ◽

Transfer Function ◽

State Space ◽

Digital Control ◽

Uncertain Parameter ◽

Electric Drives ◽

Pv Systems ◽

Space Equation

In the paper a construction of a control system for 2nd order, uncertain-parameter plant is discussed. The considered model of the plant is described by state space equation or by equivalent transfer function and it describes a huge class of real control plants, for example – electric drives or oriented PV systems. As a controller the digital proportional (P) controller was employed. The control system is going to be implemented at the microcontroller platform. Results are by the example depicted.

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Mesh Phasing Relationships in Planetary and Epicyclic Gears

Journal of Mechanical Design ◽

10.1115/1.1667892 ◽

2004 ◽

Vol 126 (2) ◽

pp. 365-370 ◽

Cited By ~ 121

Author(s):

R. G. Parker ◽

J. Lin

Keyword(s):

Dynamic Behavior ◽

Phase Difference ◽

Analytical Description ◽

Analytical Models ◽

Operating Speed ◽

The Sun ◽

Mesh Phasing ◽

Phase Relationships

The multiple tooth meshes in planetary and epicyclic gears have varying numbers of teeth in contact under operating speed, and these numbers of teeth all fluctuate at the same mesh frequency. All sun-planet meshes have the same shape and periodicity of variation of numbers of teeth in contact at the multiple meshes, but these variations are, in general, not in phase with each other. The same is true for the ring-planet meshes. Additionally, there is a phase difference between the sun-planet and ring-planet meshes. This work sets out a complete analytical description of each of these mesh phase relationships. Mesh phasing has a dramatic impact on the static and dynamic behavior of planetary and epicyclic gears. This work provides the necessary relationships to properly incorporate mesh phasing in analytical models.

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A simplified model of effective elasticity for anisotropic shales

Geophysics ◽

10.1190/1.3096616 ◽

2009 ◽

Vol 74 (3) ◽

pp. D57-D63 ◽

Cited By ~ 12

Author(s):

Audrey Ougier-Simonin ◽

Joël Sarout ◽

Yves Guéguen

Keyword(s):

Large Scale ◽

Reference Model ◽

Elastic Anisotropy ◽

Solid Phase ◽

Symmetry Plane ◽

Sedimentary Basins ◽

Bedding Plane ◽

Analytical Models ◽

Simple Method ◽

Analysis Scheme

A simple method to deal with cracklike pores in anisotropic matrix rock such as shales enhances analytical models and their applications. Actually, clayrocks (shales, in particular) are the dominant clastic component in sedimentary basins, representing about two-thirds of all sedimentary rocks. Shales are usually assumed to be transversely isotropic (TI) media. They are known to be highly anisotropic because of (1) intrinsic elastic anisotropy of the solid phase (matrix) forming the rock (more or less ordered clay layers) and (2) anisotropy induced by the presence of cracklike pores. We focus on this second component of anisotropy. Current analytical models deal with it, but they are complex and are restricted in the case of matrix TI symmetry to cracks lying in the symmetry plane. We simplify such models within a reasonably good approximation and develop an analysis scheme in which cracklike pore effects are calculated in an equivalent isotropic matrix. This simplifies the theoretical approach and potentially broadens its application to any crack and/or pore orientation, e.g., damaged shale with horizontal and vertical (perpendicular to the bedding plane) cracks. A high-pressure confinement test provides experimental data for checking the proposed tool against a reference model in the case of cracklike pores lying in the bedding plane. The results (in terms of Thomsen parameters) are consistent with results from large-scale field data.

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