| 1. |
- Berbyuk, Viktor, 1953
(författare)
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Dynamics and optimal control of biotechnical systems "Man-Prosthesis"
- 1997
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Ingår i: IUTAM Symposium on Interaction Between Dynamics and Control in Advanced Mechanical Systems, Ed. D. van Campen, Kluwer Academic Publishers, 1997. - Dordrecht : Springer Netherlands. ; , s. 35-42
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Konferensbidrag (refereegranskat)abstract
- In the paper, a mathematical model is proposed for investigating the controlled motion of human locomotion system (HLS) with an above-knee prosthesis. To provide insight into the interaction between dynamics and control in biotechnical system Man-Prosthesis the energy optimal control problem of the HLS wearing a lower limb prosthesis has been considered. The algorithm is based on special conversion of the optimal control problem for a nonlinear dynamical system which models HLS into a standard nonlinear programming problem. A number of energy-optimal control problems of human locomotion with an artificial leg, and optimization problems for the constructive parameters of the prostheses under different boundary conditions and constraints have been solved. The numerical results obtained were compared with experimental data for normal human locomotion. The energy-optimal elastic and viscoelastic characteristics of the ankle and knee joints of the prostheses have been determined.
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| 2. |
- Berbyuk, Viktor, 1953
(författare)
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On complete controllability of linear nonstationary systems
- 1993
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Ingår i: Journal of Soviet Mathematics. - 0090-4104. ; 67:2, s. 2973-2975
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Tidskriftsartikel (refereegranskat)abstract
- The concept of controllability is connected with the transfer of a dynamic system from one state to another by means of a control. An important problem in the theory of control systems is the search for necessary and sufficient conditions for complete controllability of dynamic systems. By using of the first integrals of the equations of unperturbed motion the necessary and sufficient conditions for complete controllability of linear nonstationary dynamic systems have been proposed.
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| 3. |
- Berbyuk, Viktor, 1953
(författare)
-
The use of first integrals to synthesize the energetically optimal control of a nonlinear system
- 1997
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Ingår i: Journal of Mathematical Sciences. - 1573-8795 .- 1072-3374. ; 86:2, s. 2642-2645
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Tidskriftsartikel (refereegranskat)abstract
- In the paper a method of solving problems of optimal control of the motion of nonlinear dynamical systemswith respect to energy expenditure given a fixed time and fixed ends of the phase trajectory has been proposed. The method is based on the use of first integrals of the equations of free motion. The application of the method isillustrated by examples.
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| 4. |
- Berbyuk, Viktor, 1953
(författare)
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Energy-optimal control of human leg in swing phase
- 1995
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Ingår i: Biomechanics Seminar. - 1100-2247. ; 9, s. 32-49
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Konferensbidrag (refereegranskat)abstract
- The mathematical model and efficient algorithm for designing the energy-optimal controlled processes of a human leg in the swing phase are proposed. This algorithm is based on special conversion of the optimal control problem for nonlinear dynamical system modeled a human leg into a standard nonlinear programming problem. The objective function for the optimization algorithm is the integral over swing phase's time from the sum of the mechanical power absolute values for all controlling stimuli. A number of the energy-optimal controlled processes of a human leg under different boundary conditions and restrictions on phase coordinates have been obtained. The kinematical and dynamical characteristics of obtained optimal controlled processes are compared with respective characteristics of a human leg's swing phase during normal gait.
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| 5. |
- Berbyuk, Viktor, 1953, et al.
(författare)
-
Effect of the deformability of structural links on the motion of a two-legged walking robot
- 1993
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Ingår i: Journal of Mathematical Sciences. - 1573-8795 .- 1072-3374. ; 65:6, s. 1991-1994
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Tidskriftsartikel (refereegranskat)abstract
- The problems of the dynamics and parametric optimization of the motion of a walking robot are solved within theframework of a seven-link robot's model with the elasticity of the structural components taken into account. The effect of the elasticity of the links on the kinematic, dynamic, and energy characteristics of the locomotion of the walking mechanism is studied.
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| 6. |
- Berbyuk, Viktor, 1953, et al.
(författare)
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Mathematical design of gantry robots for automating assembly processes
- 1989
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Ingår i: Soviet journal of computer and systems sciences. - 0882-4002. ; 27:2, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- A methodology for an automatic selection of the structural schema and the parameters of an assembly robot based on an optimization procedure is described. A finite collection of so-called test positions for the operating element which are determined by the robot purpose and by its characteristic movements is specified. The dynamic, strength, etc. characteristics are computed at these test positions for each structural schema and the constraints for the optimization problem are formulated. The procedure for selecting the structural schema of the robot and its technical parameters consists of minimizing some functional for the indicated constraints. An example of computing the parameters of a gantry robot is given.
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| 7. |
- Berbyuk, Viktor, 1953, et al.
(författare)
-
Modeling of human locomotion with artificial lower extremities
- 1994
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Ingår i: Biomechanics Seminar. - 1100-2247. ; 8, s. 167-178
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Konferensbidrag (refereegranskat)abstract
- To solve the problems of improvement of the existent and creation of new efficient lower limb prostheses, and to study effect of prosthesis design, as a special technical device, on kinematical dynamical energetical and other characteristics of amputee locomotion it is expedient to use wide capabilities of mathematical modelling of a human walk process on a prosthetic limb. There was proposed earlier mathematical models of biped walk having different degrees of adequacy in multitude of works. These models were used for different purposes: investigation of kinematical dynamical and energetical characteristics of human gait, working out and creation of antropomorphic walking machines, etc. In the given paper a mathematical model has been proposed for investigation of dynamics of an amputee's locomotor system with a below-knee prosthesis. Based on this model computer program has been composed. The series of problems of dynamics of a two-leggal walking, calculation of consumption of energy on motion and optimization of elastic parameters of the prosthetic foot design have been solved.
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| 8. |
- Berbyuk, Viktor, 1953
(författare)
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Multibody dynamics and optimization problems of an above-knee prostheses
- 1996
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- New prosthetic materials and designs have resulted in many prostheses of lower limbs which are presently available for the amputee to use. As a result, it is becoming more difficult for the prosthetists and the physicians to choose which prosthesis is the best for the individual amputee. Presently, there is limited information about how the prosthesis performs dynamically in achieving optimal symmetrical gait for amputee. To provide insight into the interaction between dynamics and control in biotechnical systems and for optimizing the prosthesis's structure the energy-optimal control problem of the human locomotor system (HLS) wearing an above-knee prosthesis has been considered. The algorithm based on multibody dynamics approach and special conversion of the optimal control problem for nonlinear dynamic system model of the HLS into a standard nonlinear programming problem has been proposed. A number of the energy-optimal control problems of human locomotion with an artificial leg and the optimization problems of the constructive parameters of an above-knee prostheses under different boundary conditions and constraints have been solved.
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| 9. |
- Berbyuk, Viktor, 1953
(författare)
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On the controlled rotation of a system of two rigid bodies with elastic elements
- 1984
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Ingår i: Journal of Applied Mathematics and Mechanics, Elsevier Science Ltd.. - : Elsevier BV. - 0021-8928. ; 48:2, s. 164-170
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Tidskriftsartikel (refereegranskat)abstract
- The problem of controlling the plane rotational motions of two rigid bodies connected by an elastic rod is studied. One end of the rod is attached to the support by a hinge with a spring, the latter modelling the elastic compliance of the fastening, and the other end is rigidly joined to the load. The Hamilton principle is used to obtain the integrodifferential equations and boundary conditions describing the motion of the system support — spring — rod — load. The following problem is posed: it is required to rotate the system by a given angle by means of the controlling force moment, with quenching of the relative oscillations of the load elements which appear as a result of the deformability of the rod and of the elastic torsion of the spring. Similar problem arise in the study of the dynamics and control of the motion of devices used in transporting loads through space (robots, manipulators, load lifting machines, etc.). In computing their control modes a significant part is played not only by the deformability of the elements, but also by the elastic compliance of the connecting joints. Asymptotic methods are used to botain a solution of the control problem in question for two limiting cases: 1) the mass of the load carried is much greater than the mass of the rod and support, and 2) the rod has high flexural rigidity.
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| 10. |
- Berbyuk, Viktor, 1953
(författare)
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Optimal Design of Magnetostrictive Transducers for Power Harvesting from Vibrations
- 2010
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Ingår i: Proceedings of the IMAC-XXVIII, A Conference on Structural Dynamics, The Society of Experimental Mechanics, Inc., February 1–4, 2010, Jacksonville, Florida USA. - 9781935116042 ; , s. 1-12
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Konferensbidrag (refereegranskat)abstract
- Methodology is proposed for designing of magnetostrictive electric generator having maximal mean power outputfor a given amount of active material in a transducer and a prescribed vibration excitation. The methodology isbased on dimensional analysis of constitutive linear equations of magnetostriction and numerical solution ofconstrained optimization problem in transducer’s dimensionless design parameters space by using SequentialQuadratic Programming algorithm. The methodology has been used to design optimal Terfenol-D based transducer for power harvesting from vibrations. It was shown that for steady state operations there exists possibility to choose only 4 new design parameters being the functions of dimensionless parameters of the transducer. Magnetostrictive strain derivative, Young’s modulus and magnetic permeability were determined as functions of magnetic bias and prestress by using experimental data of Terfenol-D. Contour plots and numerical analysis of design parameters show that within the considered concept of magnetostrictive electric generator there exists a set of structural parameters of the transducer that lead to its optimal performance with given amount of active material and prescribed vibration excitation. Examples of solution of optimal design problem demonstrate that for harmonic kinematic excitation with amplitude 0,0002m and frequency 100Hz it is possible to design a magnetostrictive electric generator with 3,2W mean power output having mass of active material 0,01kg.
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