Bogdan Fabiański

Dynamic model and analysis of distributed control system algorithms of three wheel vehicle

The article presents a synthesis of tricycle model with a unique concept of electric power. Conventional, mechanical coupling of a drive wheel with pedals has been replaced by the use of generator and independent motor drives. The essence of the model includes a distributed form of control system. The paper shows the genesis of the project and the motivation that results from the need to verify the condition of the vehicle in operation for a given control structure and parametres before target implementation. For the components of the model: mechanics (kinematics and dynamics), motor drives and central control system relevant mathematical equations and the corresponding signal flow block diagrams were presented. Changes effect in the control structure and in parameters on the dynamic processes occurring in the model were presented for the testing extortion that emulates human driver behavior. The analysis of simulation results were supplemented by quality indicators of the system performance important from a practical point of view. Conclusions and proposes of further research directions were presented.

Simplified model of Switched Reluctance Motor for real-time calculations

The purpose of the paper is to show a new approach for three phase, 12/8 poles SRM modeling. It was assumed that the model need to fulfill a general principles of electromagnetic energy conversion, has simple structure for fast computation and has possibility to invert for control system synthesis. The main idea bases on the replacing the non-linear flux linkage function of two variables on the product of two nonlinear functions of one variable. The analytical basis and corresponding formulas are shown in details. Two different approaches for derivation of the electromagnetic torque generation formulas are presented. The motor model implemented in the Matlab/Simulink packet is described. Simulation results with the experimental waveforms are compared what confirmed agreement of model with real object. Comparison bases on the current waveforms of three phases in selected operation points. The paper presents the way of conversion of nonlinearity from 2D arrays to the analytical form of approximated functions with only 4 parameters. Presented in the article simple, nonlinear model of SRM gives an opportunity to use in real time control systems and is dedicated for model adaptive reference structures (MRAS). The MRAS structure can be evaluated for fault detection system (FDS) and fault tolerant control (FTC) purposes. Streszczenie. W artykule przedstawiono oryginalne podejście do modelowania silnika reluktancyjnego przełączalnego. W przykładzie wzięto pod uwagę popularną konstrukcję trójpasmową o strukturze biegunów 12/8. Założono zgodność z zasadami przetwarzania energii elektromagnetycznej, prostą konstrukcję oraz zdolność do odwrócenia na potrzeby syntezy toru sterowania. Idea bazuje na zastąpieniu nieliniowej, sprzężonej funkcji dwóch zmiennych strumienia magnetycznego na wynik mnożenia dwóch funkcji jednej zmiennej. Przedstawiono podstawy analityczne idei oraz jej szczegółowe wyprowadzenia. Opisano zaimplementowany model w pakiecie Matlab/Simulink oraz wyniki badania jego zbieżności z eksperymentem w wybranych punktach pracy. Funkcje nieliniowe stablicowane w procesie wstępnej identyfikacji maszyny zostają zastąpione aproksymacjami analitycznymi z sumaryczną liczbą tylko czterech parametrów. Taki analityczny model daje się łatwo odwrócić, jego obliczenia są efektywne, a same parametry dają się stroić w procesie adaptacji do modelu rzeczywistego. Przedstawiona idea zastosowana w strukturze z modelem referencyjnem pozwala na rozwinięcie o blok funkcjonalny detekcji uszkodzeń (ang. Fault Detection System) oraz samego sterownia odpornego na awarię (ang. Fault Tolerant Control).(Model matematyczny silnika reluktancyjnego przełączalnego przeznaczony do obliczeń w czasie rzeczywistym)

Gearless Pedaling Electric Driven Tricycle

In the paper the general conception and real construction of a three-wheel bicycle with auxiliary electric propulsion is presented. Each of the vehicle wheels is driven by an electric motor (BLDC) controlled by the central system of power distribution. The generator that charges a battery pack is driven by pedals. The vehicle speed is proportional with adjustable ratio to the pedaling velocity, whereas the power delivered to the motors is appropriately increased to the pedaling power with adjustable degree. Description and analysis of the selected modules of the vehicle are documented with prototype research results.

Energetic Properties of a New, Iron Powder Based Switched Reluctance Motor Drive

The paper presents its origins as a derivative of a research grant in the topic of universal switched reluctance motor drive with powder magnetic circuit. The publication presents the results of comparison the energy performance of a prototype iron powder drive from the conventional one. The analysis of quantitative and qualitative parameters of the energy conversion process in the drive was presented. The global energy consumption statistics by electric drives to specify substance of the work of energy performance improvement was described. Introduction in power magnetic materials was done. An outline of the mechanical construction of the prototype of the engine and a dedicated control system was shown. An analysis of the compiled results, draws conclusions and proposes directions for further research were included in the end.

Switched Reluctance Motor Drive Embedded Control System

A new switched reluctance motor drive control system with real-time embedded system implementation example was presented in the paper. Genesis of the article, goals and motivation was shown. Construction of SRM with its advantages were described. Drive control system – hardware and software domain were introduced with the focus on low-resolution position feedback signal utilization in high speed drive problem. Details about phase synchronization and use of software phase locked loop were presented. Experimental results of embedded system implementation was shown to confirm the performance of introduced algorithms.

Control algorithms in distributed system of three wheeled electric vehicle

The paper presents a concept, development and comparison of selected control algorithms used in distributed control system of a three wheeled vehicle. First simulations are carried out, then the selected algorithms are tested on a real vehicle. The article includes the description of the mathematical model of the tricycle: kinematics, dynamics, motor drives, central control system, communication network and a signal flow. The mathematical model has been implemented in Matlab/Simulink environment. The vehicle uniqueness base on that it is driven with three independent BLDC drives and equipped with generator coupled with pedals. The cyclist propels the generator, whose speed (depending an control algorithm) determines the speed of the wheels. The load of the driver varies depending on the actual load of the BLDC motors. Pedaling by wire novel idea of control scheme has been applied to the trike, which means that there is no mechanical coupling (by chain or shaft) between the pedals and the wheels of the tricycle. The lack of the standard mechanical coupling enables to implement various control methods that can be focused on: dynamic (performance) of the tricycle, energy efficiency and driving comfort. The paper discusses the problem of energy distribution between cyclist and the vehicle and focuses on control algorithms determining that distribution. Simulation are verified by experiment with waveform comparison. Analysis of research results supplemented by quality indicators. Conclusions and proposes of further investigations are presented.

Parameter adaptation of simplified switched reluctance motor model using Newton and Gauss-Newton signal fitting methods

Purpose The paper is concerned about parameter adaptation of a novel, simplified and nonlinear switched reluctance motor (SRM) model. The purpose of the presented on-line procedure is to give an opportunity to set the model parameters’ values to obtain a relatively good convergence with the real control object. This is important when a reference model is used for control (e.g. optimal) or object state classification (e.g. fault detection) purposes. The more convergent the real object model is, the better operation quality may be expected. Design/methodology/approach In the paper, a 12/8 pole’s SRM as a control object is analyzed. The model equations were verified experimentally by comparing phase current model estimations with reference (measured) ones at different operational points. Differential equations of motor winding currents were chosen as an approximation function in the fitting (parameter adaptation) process using the Newton and Gauss–Newton methods. The structure of the adaptation system is presented along with the implementation in simulation environment. Findings It was confirmed in the simulation tests that Newton and Gauss–Newton methods of nonlinear model parameters’ adaptation may be used for the SRM. The introduced fitting structure is well suited for implementation in real-time, embedded systems. The proposed approximation function could be used in process as an expansion to Jacobian and Hessian matrices. The χ2 (chi2) coefficient (commonly used to measure the quality of the signal fitting) reduced to a low value during the adaptation process. Another introduced quality coefficient shows that the Newton method is slightly better in scope of the entire adaptation process time; however, it needs more computational power. Research limitations/implications The proposed structure and approximation function formula in the parameters’ adaptation system is appropriate for sinusoidal distribution of the motor phase inductance value along the rotor angle position. The inductance angular shape is an implication of the mechanical construction – with appropriate dimensions and materials used. In the presented case, the referenced model is a three-phase SRM in 12/8 poles configuration used as a main drive part of Maytag Neptune washing machine produced by Emerson Motors. Practical implications The presented method of parameter adaptation for novel, simplified and nonlinear SRM model provides an opportunity for its use in embedded, real-time control systems. The convergent motor model, after the fitting procedure (when the estimations are close to the measurements from real object), may be used for solving many well-known control challenges such as detection of initial rotor position, sensorless control, optimal control, fault-tolerant control end in fault detection (FD) systems. The reference model may be used in FD in the way of deducing signals from the difference between the estimated and measured ones. Originality/value The paper proposed a new system of parameter adaptation for the evaluated nonlinear, simplified 12/8 poles SRM model. The relative simplicity of the proposed model equations provides the possibility of implementing an adaptation system in an embedded system that works in a real-time regime. A Two adaptation methods – Newton and Gauss–Newton – have been compared. The obtained results shown that the Newton fitting method is better in the way of the used quality indicator, but it consumes more computational power.

Model and analysis of pedals ergonomic load torque angular distribution in the pedaling-by-wire system

A novel, homogeneous and continuous analytical model of cyclist pedaling torque angular distribution is presented in the article. The model is dedicated for use in an unique pedaling-by-wire system. The motivation to the research is to obtain a model for use in control system with compensation. Applying nonlinear compensation of cyclist load torque results in pedals speed ripples reduction - particularly noticeable at high torque loads. Theoretical assumptions to the model are described in the article with use of kinematics relations marked both on vehicle photography and detailed sketches. Inverse kinematics formulas are verified by comparison two different methods of formulating the kinematic equations of the model. Those methods bases on geometric and vector approach are different in computation complexity. The model of dynamics is presented with its physical fundamentals explanation. Adaptation system of presented model parameters is introduced basing on the Gauss-Newton algorithm. Fitting process is described on the example of three experimental reference data acquired at three different torque loads. Final results of parameters adaptation are presented in the graphical and numerical way by using chi2 coefficient. Further research plans based on obtained results are included in the article summary section.