Showing papers in "Elektronika Ir Elektrotechnika in 2014"

Modified Bat Algorithm

Abstract: Heuristic optimization algorithms which are inspired by nature have become very popular for solving real world problems recently. The use of these algorithms increases day by day in the literature because of their flexible structures and non-containing confusing mathematical terms. One of these algorithms is Bat Algorithm (BA). BA is a heuristic algorithm based on echolocation characteristic of bats and developed by the mimics of bats’ foraging behaviour. In this study exploration mechanism of the algorithm is improved by modifying the equation of pulse emission rate and loudness of bats. The performance of Modified Bat Algorithm (MBA) is verified by 15 benchmark functions and the results were exhibited as comparative. The results of MBA are superior in terms of solution quality on optimization problems compared to BA. DOI: http://dx.doi.org/10.5755/j01.eee.20.2.4762

Z-Copy Controlled-Gain Voltage Differencing Current Conveyor: Advanced Possibilities in Direct Electronic Control of First-Order Filter

Abstract: A modified version of voltage differencing current conveyor (VDCC) and its performance in detail is presented in this paper. Modified VDCC, so-called z-copy controlled gain voltage differencing current conveyor (ZC-CG-VDCC), offers interesting features from adjustability point of view. The active element allows independent electronic control of three adjustable parameters: intrinsic resistance of current input terminal, transconductance and current gain of the output stage which is not possible in case of conventional VDCC. The characteristics of proposed CMOS implementation designed using TSMC LO EPI 0.18 m technology process parameters are shown and discussed. Simple application in reconfigurable reconnection-less first-order voltage-mode multifunctional filter is shown and verified by SPICE simulations and experimentally. The filter tuning and change of the transfer function type is allowed by the controllable parameters of the ZC-CG-VDCC. DOI: http://dx.doi.org/10.5755/j01.eee.20.6.7272

PA-NEMO: Proxy Mobile IPv6-aided Network Mobility Management Scheme for 6LoWPAN

Abstract: The IPv6 over Low Power Wireless Personal Area Network (6LoWPAN), a special type of Wireless Sensor Networks (WSNs) with mobility, has a great potential to be deployed for the convenience of people’s life. In 6LoWPAN, a group of sensor nodes often move together as a whole subset, guiding by a cluster head. Because of the low-power requirements of mobile devices in 6LoWPAN, seeking low cost schemes to manage the mobility of the whole subset is a very essential problem to be solved. To this end, this paper firstly proposes a Proxy Mobile IPv6 (PMIPv6) Aided Network Mobility (NEMO) management scheme, referred to as PA-NEMO, for 6LoWPAN, by combining traditional PMIPv6 with NEMO Basic Support scheme. In the proposed PA-NEMO scheme, the transmission tunnels are established out of the 6LoWPAN area, so the cost of the devices can be greatly reduced. Then, we formulate and analyse the signalling overhead of the proposed PA-NEMO. Finally, some numerical results are presented to show that our proposed PA-NEMO achieves the lowest signalling overhead among existing mobility management schemes. DOI: http://dx.doi.org/10.5755/j01.eee.20.3.3951

Second-order Simple Multiphase Oscillator Using Z-Copy Controlled-Gain Voltage Differencing Current Conveyor

Abstract: Interesting type of the second-order electronically controllable multiphase oscillator is introduced in this paper. Modified voltage differencing current conveyor, so-called z-copy controlled gain voltage differencing current conveyor (ZC-CG-VDCC), offers interesting features for synthesis of this type of multiphase oscillator. Available controllable parameters of the ZC-CG-VDCC (intrinsic resistance, transconductance and current gain) are fully utilized for independent adjusting of oscillation condition and oscillation frequency. Specific matching condition allows linear control of oscillation frequency that is not so typical in such simple types of oscillators. Available phase shifts are 45, 90, 135 and 180 degree. Simulation results based on CMOS model of active element confirms intentions of the proposal in the bandwidth of several MHz. DOI: http://dx.doi.org/10.5755/j01.eee.20.9.8709

Implementation of a New Contactless Piezoelectric Wind Energy Harvester to a Wireless Weather Station

Abstract: A newcontactless piezoelectric (PZT) wind energy harvester is constructed and a feasibility study on its power generationmechanism is carried out for a wireless weather station. The new harvester has a magnetic unit enabling to vibrate aPZT layer in a contactless manner. The poles of magnets are oriented in such a way that the tip of the layer is always repelled, when wind rotates the harvester shaft. Therefore the produced magnetic force exerts mechanical bucklings on the layer and this effect produces electricity. After one-year operation, it is clarified that an averaged power of 20 µW–60 µW can be obtained monthly for the feeding of the station. These results prove that 5 %–18 % of the consumed power of wireless station can be generated by the harvester depending on the wind regime in the region. DOI: http://dx.doi.org/10.5755/j01.eee.20.10.8871

Optimization of the Fast Image Binarization Method Based on the Monte Carlo Approach

Abstract: The paper concerns the problem of fast image processing in the low computational power systems with limited memory, which are typical for robot vision and embedded systems. Assuming the necessity of decision based on incomplete information when the amount of visual data is too big for an efficient processing, the reduction of their amount becomes a crucial element of the processing system. A good classical example may be histogram based image binarization which requires the knowledge of the distribution of intensities for the whole grey-scale image. Applying the Monte Carlo method for the reduction of the amount of data, much smaller images with similar statistical properties may be obtained, which can be further used for thresholding and binarization e.g. using Otsu algorithm. A relevant problem in this approach is the proper choice of the number of samples for the Monte Carlo method which influences the result of binarization. In this paper the method based on the analysis of image entropy or energy changes is proposed for this purpose. Obtained results, verified for various images, are promising even for relatively small number of samples used for the estimation of the histogram. DOI: http://dx.doi.org/10.5755/j01.eee.20.4.6887

PV Supplied Single Stage MPPT Inverter for Induction Motor Actuated Ventilation Systems

Abstract: Ventilation and refrigeration is indispensable process for human life. Particularly, it has vital importance in desert climate conditions and rural areas, where the grid power may not be available. Although the cost is still higher than traditional energy resources, renewable energy may be the right choice for these applications. In this paper, a DSP based variable speed drive for induction motors to actuate a ventilation system supplied photovoltaic arrays is proposed. The maximum power point of the photovoltaic arrays is tracked by proposed variable speed drive. A variable stepped incremental conductance and constant voltage methods are combined to obtain fast tracking algorithm which generates voltage and frequency references for three phase three level inverter. Also the switching frequency of the inverter is kept constant to improve the quality of current waveform at low power levels. Experimental results show that, the proposed system has fast reaction and is suitable for rapidly changing irradiation level. Since the additional converter requirement is eliminated by using single stage inverter, the total system efficiency is increased. DOI: http://dx.doi.org/10.5755/j01.eee.20.5.7111

Determination of Passive and Semi-Passive Chip Parameters Required for Synthesis of Interrogation Zone in UHF RFID Systems

Abstract: In this paper, authors disclose the methodology of interrogation zone synthesis that comprehensively covers all aspects connected with determination of RFID device parameters. The effective methods of involved parameter determination for passive and semi-passive UHF RFID chips are presented. The elaborated measuring procedures have been verified experimentally and are discussed in details. The special untypical laboratory stand has been prepared for carrying out the research tasks. Furthermore, the importance of the parameters for the interrogation zone synthesis is described methodically. In addition, the special software tools that allow researchers to effectively conduct investigations on protocol parameter modifications both in new-developed as well as approved standards (e.g. ISO/IEC 18000-6c) have been designed. These facilities can significantly support many theoretical and simulation works that are developed and described in the branch literature and can improve the reliability and efficiency of designed RFID applications. DOI: http://dx.doi.org/10.5755/j01.eee.20.9.5007

Packet Inter-arrival Time Distribution in Academic Computer Network

Abstract: The article presents the statistical analysis results of network packet inter-arrival time distribution in academic computer network. Most popular transport protocols TCP and UDP are addressed in the research. Data was gathered using NetFlow protocol. Network traffic was divided into sections according its direction and usage trends, then packet inter-arrival time distributions were found. Kolmogorov-Smirnov test was used to evaluate goodness-of-fit of packet inter-arrival time distributions and it was determined, that Pareto Second Kind distribution fits the majority of the experimental distributions. DOI: http://dx.doi.org/10.5755/j01.eee.20.3.6683

Powering Environmental Monitoring Systems in Arctic Regions: A Simulation Study

Abstract: This paper describes a long-term simulation of an environmental monitoring system. This innovative approach combines harvesting-aware power management with primary batteries used as a back-up. It significantly extends the operational life of the device, while avoiding loss of data due to insufficient solar energy during winter in the harsh Arctic environment. The simulation considers the device to be located in the Arctic environment. Its main operation modes involve measurement from sensor interface, data storage and transmission. To perform an effective data-for-energy exchange, the device is controlled by a fuzzy energy management strategy. The new structure of the fuzzy rule-based system independently controls two separate variables related to data collection and the operation of a data buffer. The simulator uses meteorological data from Inuvik, Northwest Territories, Canada, to estimate the amount of energy available for solar harvesting. This site, located above the polar circle, receives very limited amounts of solar radiation during winter. Operation of the device is evaluated over a two-year period. The simulation results are described both numerically and using time-series plots of energy- and data-related variables. The performance is adequate for unsupervised operation of the system with annual maintenance visits to replace batteries. DOI: http://dx.doi.org/10.5755/j01.eee.20.7.8020

An Improved Risk Assessment Method for SCADA Information Security

Abstract: In this paper, we address information security risk analysis in SCADA systems and propose an improved security risk assessment method in the case of attacks on the SCADA information and communication infrastructure. The assumption is that intrusion prevention/detection systems are implemented as security mechanisms. The proposed method has been demonstrated on an example of the SCADA system in a hydropower plant. Cost-benefit analysis has been performed on the basis of the Return on Security Investment. DOI: http://dx.doi.org/10.5755/j01.eee.20.7.8027

Electronics for Ultrasonic Imaging System

Abstract: Design of ultrasonic imaging system is presented. System has a modular structure with main acquisition and front end electronics separated in order to have minimal path for host PC connectivity and shortest path to ultrasonic transducer. Such acquisition modules placement allows reducing the induced EMI and increasing the flexibility of the system. Positioning module is also separate and allows various scanning equipment configurations. Evaluation of excitation and reception electronics parameters is presented. Essential measurement procedures outlined. Signal digitization parameters (sampling frequency, clock jitter and quantisation) were chosen to balance time of flight estimation random errors versus interpolation bias errors. DOI: http://dx.doi.org/10.5755/j01.eee.20.7.8024

Indirect Measurement of Motor Current Derivatives in PMSM Sensorless Drives

Abstract: Motor current derivatives contain useful information for control algorithms, especially in sensorless electric drives. The measurement of motor current derivatives in electric motors supplied by voltage source inverter can be performed using di/dt transducers. However, in such a solution additional sensors have to be installed, e.g. Rogowski coils. Another approach is to measure current derivatives indirectly – by oversampling the motor currents. In such a method special attention must be paid to determination of current sampling instants. Measurement triggering times must be recalculated in each voltage modulation period with regard to transistors switching. The paper presents different current sampling approaches. Considered oversampling algorithms were experimentally tested in sensorless PMSM drive. The impact of different sampling approaches on the accuracy of rotor position estimation has been discussed. DOI: http://dx.doi.org/10.5755/j01.eee.20.7.8019

Method for Recognition of the Physical Activity of Human Being Using a Wearable Accelerometer

Abstract: Companies are interested in retaining workers healthy, productive, and satisfied while cutting health-care and insurance costs. Using a computer at work can cause back, neck and shoulder pain, eyestrain, and overuse injuries of human hands and wrists. It is possible to reduce these risks with better posture and good habits, such as taking rest breaks. During these breaks computer users should be encouraged to stand, stretch, and move around. For people who forget about a break or truly are focused on their direct work need help from special equipment for evaluation of real physical activity of computer user. Method for recording accelerometer data from moving human as he or she performs daily activities and for identification of type, duration and intensity of movements by using wearable wireless sensing system is presented in this paper. The extraction of orientation independent acceleration data has positive effect on recognition accuracy of k-nearest neighbour classification scheme used for classification task. The recognition accuracy of algorithm is 78.9% and these results are better than accuracy obtained from raw accelerometer data. The method presented is simple, exhibited good performance and does not require significant computational recourses. DOI: http://dx.doi.org/10.5755/j01.eee.20.5.7113

Analysis and Modeling of Converter with PWM Output for Two-Phase Motor Applications

Abstract: This paper presents a steady state analysis of two-phase voltage-source converters with pulse width modulation (PWM) and output voltage control for small two-phase motor drives. The mathematical models of the different converter connections are built on condition of assumption of idealized semiconductor devices. A complex Fourier series approach is used to predict to terminal voltage and current waveforms. DOI: http://dx.doi.org/10.5755/j01.eee.20.1.6160

Bee-MANET: A New Swarm-based Routing Protocol for Wireless Ad Hoc Networks

Abstract: Recently, mobile ad hoc networks (MANETs) have drawn attention by many researchers due to the development of portable devices and wireless network appliances have accounted for ad hoc networks. Many academic researchers have shown great interest in ad hoc networks for twenty years. One of the main fields adopted by researchers studying on Mobile Ad-hoc Networks is to develop routing protocols in wireless systems. Routing protocol development is related to complexity, scalability, adaptability, productivity, and battery life in wireless systems. Routing protocols for wireless systems are developed in order to cope with these problems. In this paper, a new routing protocol for mobile ad hoc network (Bee-MANET) was presented to improve network throughput. Bee-MANET, AODV and Beeadhoc routing algorithms for MANETs are empirically compared in order to research their large-scale behaviors. The results presented as graphs and brief discussion is given. DOI: http://dx.doi.org/10.5755/j01.eee.20.3.3421

An improved Synchronous Control Strategy based on Fuzzy controller for PMSM

Abstract: In industry, rail gnawing phenomenon often appears in the synchronous operation of crane. An improved synchronous control strategy for a dual permanent magnet synchronous motor (PMSM) servo system is proposed in this paper. To achieve a synchronous performance with robustness, a cross-coupled synchronous system based on the virtual electronic shaft which both torque and speed are used as feedback signals is developed. Two fuzzy PID compensators with accurate approximation capability based on programmable logic controller (PLC) is implemented to estimate the lumped uncertainty. In the computer simulation, the improved synchronous control strategy is proved to have strong ability to adjust for the external disturbance, and have both smaller convergence time and tracking error. Some experimental results are illustrated to depict the validity of the proposed control approach, which can effectively inhibited wheel’s rail gnawing phenomenon in crane. DOI: http://dx.doi.org/10.5755/j01.eee.20.6.7261

Laser Line Detection with Sub-Pixel Accuracy

Abstract: Due to the fact that the image sensors have a fixed resolution and pixel size – a lot of image processing algorithms are limited with pixel resolution. One of those image processing algorithms is related to 3D laser scanners and in particularly to the laser line detection from images. This pixel quantization resolution, however, in many cases is not sufficient and greatly limits the laser scanner precision. In particularly the problem is highlighted in the linearly growing or declining surfaces, but also in strait lines where the actual laser line centre position is between two pixels. In this paper two laser line centre position detection methods with sub-pixel accuracy have been proposed and investigated. The methods have been tested on real images and as seen from the results at the end of the paper, the methods greatly improve the laser line detection accuracy and resolution. DOI: http://dx.doi.org/10.5755/j01.eee.20.5.7114

Simple Computational Method of Predicting Electrical Characteristics in Solar Cells

Abstract: A precise single-diode analytical model of Photovoltaic (PV) modules is generally nonlinear analytical equations with high computation complexity. This paper proposes a simple computational method for the PV model. Its exponential diode behaviour is simplified via Least Squares Approximation (LSA), which permits designers or engineers to predict the electrical characteristics of a PV module without using iterative numerical calculations. Based on experimental data, the methodology is validated by covering a wide range of operation conditions. Simulation and experimental results prove the effectiveness and accuracy of the proposed method. DOI: http://dx.doi.org/10.5755/j01.eee.20.1.6165

Identification of Low Voltage AC Series Arc Faults by using Kalman Filtering Algorithm

Abstract: Arc faults often occur in residential low voltage AC supply environment. It is dangerous because the sparks accompanying with arc faults may lead to electric fire even safety hazard. Effective methods of arc faults diagnosis in circuits are essential for safety interrupters in household. A novel method for low voltage AC series arc faults identification based on time-domain feature extraction by using Kalman filtering algorithm is proposed in this paper. This method monitors the instantaneous value of series current in circuits, calculates an elaborate pre-designed eigenvalue each power cycle by using Kalman filter with acquired current samples, and compares the eigenvalue with a reference value. Once the deviation between them exceeded a predefined threshold in continuous eight power cycles, the method reports an arc fault. Experimental research was studied in laboratory with typical electrical loads using the proposed arc faults identification method. Results show that it is applicable to detect arc faults within eight power cycles. The response time of the method could fit the minimum requirements of the standard UL1699. DOI: http://dx.doi.org/10.5755/j01.eee.20.5.4294

Fast Matrix Covering in All Programmable Systems-on-Chip

Abstract: The paper suggests a technique for solving the matrix/set covering problem in all programmable systems-on-chip. A novel very fast hardware accelerator is proposed and implemented in the programmable logic (PL) of a Xilinx Zynq microchip. The accelerator is managed by software running in the processing system (ARM Cortex-A9) available on the same microchip and communicating with the PL through high-speed interfaces. The results of implementation, experiments, and comparisons demonstrate significant speedup comparing to software running in general-purpose PC and in the ARM. DOI: http://dx.doi.org/10.5755/j01.eee.20.5.7116

Emotion Recognition in Human Computer Interaction Systems

Abstract: In order to ensure comfortable life human computer interaction (HCI) systems are widely used in the smart home. It is important to detect and respond to the smart home residents’ emotional state and reduce stress levels. The HCI system for emotional state recognition is developed. This paper deals with stressful state recognition by means of the heart rate variability (HRV) analysis, because it is a non-invasive method. The emotional state should be identified in the situations which correspond to real life at home: a person sits, walks, and changes his/her posture over time. The impact of the emotional state and the posture impact on heart rate variability are examined. Time domain, frequency domain and nonlinear parameters are calculated. The parameters that are most sensitive to the emotional state are chosen. Variability of the HRV parameters are verified over time. It was found that posture has a great impact on the HRV parameters, so posture detection subsystem is integrated in our HCI system for emotion recognition. The subject- dependent thresholds should be used for emotional state recognition. DOI: http://dx.doi.org/10.5755/j01.eee.20.10.8878

Comparison of Automatically Tuned Cascade Control Systems of Servo-Drives for Numerically Controlled Machine Tools

Abstract: Servo-drives have a significant influence on the tracking accuracy of numerically controlled machine tools. It is important to properly choose the structure and gains of a servo-drive control system. This paper presents a tuning method for position and velocity controllers of digital servo-drives. The proposed method allows the controllers’ gain values regardless of controller types (P, PI, PD or PID) to be determined. It takes into account a number of parameters relevant to practical applications, such as the shape of the position error signal and the resolution of the transducer used to measure the angular position of the motor shaft. The controller gains are determined for a parabolic position command signal. A comparison of the influence of both controllers’ types and feed-forward control types on tracking error is also presented. DOI: http://dx.doi.org/10.5755/j01.eee.20.3.2788

Examination of Electromagnetic Noises and Practical Operations of a PMSM Motor driven by a DSP and Controlled by means of Field Oriented Control

Abstract: This paper presents main problems of practical implementation of filed oriented control (FOC) dedicated for a permanent magnet synchronous motor (PMSM). By means of this work, elements of FOC’s mathematical model and practical implementation of the electronic commutator are presented. It is based on the DSP processing unit IGBT power module. The measurement system consists of control unit equipped with inverter and encoder. The main element of driving system is PMSM drive. There are two main problems addressed in this paper: electromagnetic distortions and proper calculations in real systems. This work is intended to resolve these problems. Described solutions have been implemented and examined practically. DOI: http://dx.doi.org/10.5755/j01.eee.20.5.7099

Modelling the Cell Transmembrane Potential Dependence on the Structure of the Pulsed Magnetic Field Coils

Abstract: During high power pulsed magnetic field treatment of biological samples the cells are subjected to both the high magnetic and induced electric fields. The extent of the influence of each treatment component is poorly studied. The work presents the finite element method analysis of pulsed inductive coils that are used for generation of pulsed magnetic and induced electric fields. The simulated coils, electrical parameters and the output characteristics are evaluated in respect to the induced cell transmembrane potential. The model of the Jurkat T lymphocyte cells is introduced in the analysis. The study includes finite element method analysis of four solenoid coils with different structure and inductance in the range of 2.8 μH to 62 μH. Pulsed magnetic field amplitudes up to 5 T are investigated in this work. DOI: http://dx.doi.org/10.5755/j01.eee.20.8.8432

Application of Stochastic Differential-Algebraic Equations in Hybrid MTL Systems Analysis

Abstract: The paper deals with the application of stochastic differential-algebraic equations (SDAE) in the field of the time-domain simulation of hybrid (lumped/distributed) systems with randomly varying parameters. A core of the method lies on the theory of stochastic differential equations (SDE) considering the system responses as stochastic processes. However, due to a hybrid nature of the system, namely its lumped parameter part, non-differential (algebraic) parts arise generally in the solution. Herein, multiconductor transmission lines (MTL) play a role of the distributed-parameter parts of the hybrid system. The MTL model is designed as a cascade connection of generalized RLCG T-networks, while the state-variable method is applied for its description. The MTL boundary conditions are incorporated through a modified nodal analysis (MNA) to cover arbitrarily complex circuits. System responses are formed by the sets of stochastic trajectories completed by corresponding sample means and respective confidence intervals. To get the results a weak stochastic backward Euler scheme is used, consistent with the Ito stochastic calculus. All the computer simulations have been performed in the Matlab language environment. DOI: http://dx.doi.org/10.5755/j01.eee.20.5.7098

Linear Model of a Novel 5-Phase Segment Type Switched Reluctance Motor

Abstract: This paper introduces the general linear magnetic circuit model of a novel 5-phase segment type switched reluctance motor (ST-SRM) of which rotor cores are embedded in an aluminum block as well as to improve the performance characteristics under simultaneous two-phase (bipolar) excitation of windings. The developed model implements the magneto motor force (mmf) that is necessary to produce short and exclusive magnetic flux paths minimizing the commutation switching and eddy current losses in the laminations. For this purpose, an equivalent magnetic circuit for newly developed ST-SRM and the underlying assumptions are given. The concept of apparent inductance and torque equations of two-phase simultaneously excited ST-SRM is introduced and the effectiveness and deficiencies of the linear model are given. DOI: http://dx.doi.org/10.5755/j01.eee.20.1.6159

Grounded Voltage Controlled Positive Resistor with Ultra Low Power Consumption

Abstract: In this work, a new CMOS based grounded voltage controlled positive resistor (GVCPR) with one control voltage is proposed. The proposed GVCPR employs only five CMOS transistors, one operated in triode region and others operated in saturation region or OFF. One of the main properties of the proposed GVCPR is its ultra low power consumption; however, a single active component matching condition is needed. A number of SPICE simulation results using IBM 0.13 μm SIGE013 level-7 CMOS process parameters such as its performance analysis and verification in tunable voltage-mode first-order all-pass filter and high-Q & high-gain voltage-mode multiple-feedback second-order band-pass filter are included to confirm the theory. The superior performance of the proposed GVCPR is also proven by numeric Figure of Merit calculation. DOI: http://dx.doi.org/10.5755/j01.eee.20.7.8023

A Unified SLAM Solution Using Partial 3D Structure

Abstract: Good quality of environment mapping demands modelling the associated environment nearly to its 3D originality. This paper presents a unified Simultaneous Localisation And Mapping (SLAM) solution based on partial 3D structure. As compared to existing representations such as grid based mapping, the novelty of the proposed unified approach lies in estimation, representation and handling of compact partial 3D features-based map model for a team of robots that are working in an unknown environment with unknown poses. The approach replies on a camera to perceive the environment and a 2D laser sensor to generate a SLAM solution with partial 3D features based representation. Extended Kalman Filter (EKF) estimates the robot pose based on its motion model and map of the explored environment. The solution has been tested in an indoor environment on two identical custom-developed robots. Experimental results have demonstrated efficacy of the approach. The presented solution can be easily applied on a distributed/centralized robotic system with ease of data handling and reduced computational cost. DOI: http://dx.doi.org/10.5755/j01.eee.20.9.8707

Hexapod Robot Energy Consumption Dependence on Body Elevation and Step Height

Abstract: Walking robots are well known for being able to walk over rough terrain and adapt to various environments. Hexapod robots are chosen because of their better stability and higher number of different gaits. However, having to hold the whole weight of the body and a large number of actuators makes all walking robots less energetically efficient than wheeled machines. Special methods for energy consumption optimization must be found. In this paper, hexapod robot energy consumption dependence on body elevation and step height is presented. Three main hexapod gaits are used: tripod, tetrapod and wave. Experimental results show that energy consumption does not depend on body elevation or gait. Although, higher steps increases the power consumption. Therefore, when walking over even terrain, lower step heights along with higher body elevation must be selected for tripod or tetrapod gait in order to surpass ground irregularities but still maintain maximum energetic efficiency. DOI: http://dx.doi.org/10.5755/j01.eee.20.7.8017