Advances in Intelligent Systems and Computing, 2015
This paper presents a new hyper-redundant robotic arm structure and its sensorial, driving and co... more This paper presents a new hyper-redundant robotic arm structure and its sensorial, driving and control systems. A system of cables actuated by DC motors is used for bending. The position of the robot can be obtained by bending it with the cables and by blocking the position of the needed elements using an electro pneumatic system. The major advantage of this type of actuator consists in the fact that the robot can be moved using a boundary control by cables with a single actuating unit, the position blocking system for any element being relatively simple. The main features and advantages of the sensorial system and global robot system are presented. The dynamic model of the arm is developed using Lagrange’s formalism; the motion control system is based on the adaptive computed-torque method. Finally, experimental results are described.
2014 18th International Conference on System Theory, Control and Computing (ICSTCC), 2014
The curvature control problem for a class of hyper-redundant robot arms with continuum elements c... more The curvature control problem for a class of hyper-redundant robot arms with continuum elements characterized by an elastic backbone system is analyzed. The main parameters of the arm shape as curvature and curvature gradient are estimated. The stability analysis and the resulting controllers are obtained using the concept of boundary geometric control and a weighted state control methods. The proposed algorithm determines the control solutions using the dynamic model expressed in terms of curvature parameters. The objective of this paper is the curvature control problem of a tentacle arm with continuum elements HHR 02 (Hybrid Hyper-redundant Robot 02). Numerical simulations illustrate the effectiveness of the presented algorithms and techniques.
2013 17th International Conference on System Theory, Control and Computing (ICSTCC), 2013
This paper presents the structure of a backbone hyper-redundant arm with an electro-pneumatically... more This paper presents the structure of a backbone hyper-redundant arm with an electro-pneumatically system for position control. A system of cables actuated by DC motors is used for bending. Control system is based on a PIC microcontroller. The position of the robot can be obtained by bending it with the cables and by blocking the position of the elements we need, using the electro-pneumatically system. The major advantage of this type of actuation consists in the fact that the robot can be actuated using a boundary control by cables, the position blocking system for any element being relatively simple. The actuating system and the PIC microcontroller system is described and the main features of the global system are presented. The advantages of this robot architecture are discussed.
2014 18th International Conference on System Theory, Control and Computing (ICSTCC), 2014
This paper presents the sensorial system for structure of a backbone hyper-redundant arm with an ... more This paper presents the sensorial system for structure of a backbone hyper-redundant arm with an electro-pneumatically system for position control. A system of cables actuated by DC motors is used for bending. Control system is based on a PIC microcontroller. The position of the robot can be obtained by bending it with the cables and by blocking the position of the elements we need, using the electro-pneumatically system. The major advantage of this type of actuation consists in the fact that the robot can be actuated using a boundary control by cables, the position blocking system for any element being relatively simple. The sensorial system is described and the main features of the global system are presented. The advantages of this sensorial system for this robot architecture are discussed.
This paper is a component of a research project regarding the design and development of an Intell... more This paper is a component of a research project regarding the design and development of an Intelligent Haptic Robot-Glove for the rehabilitation of the patients that have a diagnosis of a cerebrovascular accident. In this paper, the control system for a rehabilitation hand exoskeleton is discussed. In order to avoid the complex problems given by a distributed sensor network, this paper treats the problem of the compliance force control by using observers: a velocity observer, a force observer and a disturbance observer. Two control solutions are discussed. First, the disturbance effects are eliminated by a cascade closed loop control with velocity and force observers. Then, a disturbance observer is used to compensate the compliance effects. The performance of the control systems is demonstrated by the simulation.
2013 19th International Conference on Control Systems and Computer Science, 2013
ABSTRACT This paper is based on the results of a research project regarding the design and develo... more ABSTRACT This paper is based on the results of a research project regarding the design and development of an Intelligent Haptic Robot-Glove (IHRG) for the rehabilitation of the patients that have a diagnosis of a cerebrovascular accident. The IHRG is an exoskeleton that supports the human hand and hand activities by using a control architecture for dexterous grasping and manipulation. The five-fingered assistive robotic glove is designed with mechanical compliance of human finger. The biomechanical elements of the exoskeleton assistive hand are designed considering: motion in different planes, adapted to patient's hand, possible to train pinch and grasp, opening/closing game. The actuation system is also studied and designed. The paper provides an overview of hand rehabilitation and evaluation techniques.
This paper studies the dynamic model of the continuum robots as a fractional order system. The vi... more This paper studies the dynamic model of the continuum robots as a fractional order system. The viscoelastic Kelvin-Voigt model is applied and a fractional order system is proposed and discussed. The distributed model is transformed in a nonlinear fractional order system by a weighting technique of the state variables. A control law defined with respect to direct observable variable, with a physical meaning, is proposed. A fractional order observer is proposed. The frequential criterions that ensure the asymptotical stability of the global model“observer-system“ are discussed. Numerical simulations and experimental results confirm the quality of the proposed algorithms.
In this paper is presented an experimental test stand of rheological stop-valves. Rheological sto... more In this paper is presented an experimental test stand of rheological stop-valves. Rheological stop-valve structures are robust, simple in terms of constructive and easy to control. However, due to non-Newtonian fluid flow rheological, are difficult to model mathematically. Since many parameters of these valves are determined empirically, and depend very much on the constructive parameters, it is necessary to determine them experimentally. The paper also presents a stand designed, developed and tested for magneto-rheological stop valves. This is shown schematically speaking, constructive and programming. The stand allows the experimental determination of parameters valves, their dependence on the type of fluid used and the type rheological field excitation applied to the fluid. Determination of valve parameters can be made for any type of field excitation. Applied voltage generator may be continuous, can be generated with a constant frequency or a frequency dictated by the law of ord...
The paper aims to study the applicability and limitations of the solution resulting from a design... more The paper aims to study the applicability and limitations of the solution resulting from a design process for an intelligent system supporting people with special needs who are not physically able to control a wheelchair using classical systems. The intelligent system uses information from smart sensors and offers a control system that replaces the use of a joystick. The necessary movements of the chair in the environment can be determined by an intelligent vision system analyzing the direction of the patient’s gaze and point of view, as well as the actions of the head. In this approach, an important task is to detect the destination target in the 3D workspace. This solution has been evaluated, outdoor and indoor, under different lighting conditions. In order to design the intelligent wheelchair, and because sometimes people with special needs also have specific problems with their optical system (e.g., strabismus, Nystagmus) the system was tested on different subjects, some of them...
2018 22nd International Conference on System Theory, Control and Computing (ICSTCC), 2018
Hyper-redundant robots of backbone types are generally driven by traction cables, making differen... more Hyper-redundant robots of backbone types are generally driven by traction cables, making different curves for different segments in their body. This paper presents the structure of a hyper-redundant robot of backbone type having an electro- rheologhic system for position control. For proper operation, so for bending, we uses a cables system with DC motor-driven. The control system is made with a PIC microcontroller. Modeling the robot's position is done by bending it with cables, combined with locking the desired elements position through the electro- rheological system. The major advantage of this type of drive lies in the fact that the robot modeling can be done with a system with only three cables, the position lock system of an element or segment is relatively simple. Also presented is a variable width signal system with constant amplitude where the duration of the input signal is the control variable. The control system uses a mixed control. We use this controller for contr...
2020 24th International Conference on System Theory, Control and Computing (ICSTCC), 2020
This paper focuses upon the detection of a tumor in one of the most common cancer in men, the pro... more This paper focuses upon the detection of a tumor in one of the most common cancer in men, the prostate cancer. The aim is to find out new methods to investigate this class of tumors, to identify the current state and their evolution. New algorithm to perform the prostate cancer cell analysis is proposed. The RGB color system of the cell is interpreted as a 3-D surface and the fractal analysis is performed. The Hölder exponents of this surface are investigated and the spectral analyze of the singularities is inferred. Spectral estimation is considered as one of the main factors that characterizes the surface irregularities. The granularity of the cells is investigated by the binary analysis of the grey image. An evaluation of the area of the light color subdomains is performed. A classification coefficient based on these two investigations is proposed.
In medicine, a prosthesis or prosthetic implant is an artificial device that replaces a missing p... more In medicine, a prosthesis or prosthetic implant is an artificial device that replaces a missing part of the body, which can be lost through trauma, disease, or illness present at birth. To help these amputated people, transtibial prostheses have been developed that have the role of increasing the motor abilities of the person in question. Among the different models of prostheses, the most frequently used are non-articulated prostheses, articulated prostheses, prostheses with energy re-turn/dynamic response, and microprocessor-controlled prostheses. The foot can vary the flexibility and elasticity of the complex structure to perform various challenging tasks, such as running, climbing, balancing, jumping, and lifting on the toes. To replace these functions, prostheses with different design and operating modes are used, depending on the activity performed. Thus, a person with social activity, or sports activity, requires the use of several prostheses with different modes of operation....
A heating and climatizer system based on selective absorption of solar energy by a selective coll... more A heating and climatizer system based on selective absorption of solar energy by a selective collector. The experimental study shows that the performance of this system depends on several variables: the nature of the colporteur fluid, the flow of the fluid circulation, the collector's surface area and the circulation mode (opened or closed circulation). The system was tested inside a building which contained a strawberry crop. A clear improvement of the performance has been achieved for an open circulation with appropriate working variables. The experimental results showed precocity of 14 days of the strawberry crop in comparison to a standard building. The variables of the experiment that can be controlled are: the flow of evacuated fluid, the entrance flow, the temperature of the fluid and the positioning of the transducer/ hole test. However, the measurement of these variables is affected by errors which cannot be completely eliminated.
The modularity of robotic subsystems is a big opportunity for robotics to compel recognition on t... more The modularity of robotic subsystems is a big opportunity for robotics to compel recognition on the market as a viable and efficient alternative, thanks to the development of standardized modulus, especially, but also because of the robots' features-such as productivity and flexibility. The idea of this proposal roots in the structure of a personal computer. The winding and the upgrade of a pc is an extremely simple and quick process thanks to the standardization of the functional modulus. Extrapolating this idea to robots, and to robotic systems, in general, it is necessary the conceiving of a modular system, as far back as in the primary design phase. The modular system should be conceived as intelligent structures with a high degree of sensorial, communicational, functional and control autonomy. These elements are presented and experimented with functional models, for validation. The conclusions are formulated and future directions are targeted.
2019 23rd International Conference on System Theory, Control and Computing (ICSTCC), 2019
Hyper-redundant robots are designed to work in space with restrictions. From the point of view of... more Hyper-redundant robots are designed to work in space with restrictions. From the point of view of the mobility of the discrete hyper-redundant robots, two constructive types are consecrated. With extreme mobility (element level actuating), a solution that requires actuators in each joint, to the detriment of weight and hence the length. With a large length (actuators in the base, and traction cables), a solution that increases the length of the robot against the mobility. In this paper, the authors propose a joint actuating solution that solves this problem. The proposed actuating system is a hybrid structure, based on pneumatic control with an electrorheological element. It made of a pneumatic actuation with kinematics and dynamics fully controllable based by a structure with an electrorheological stop valve. Also, the proposed electrorheological stop-valve solution reduces the limitations imposed on the fields of application of electro-rheological fluids, limitations due to the hi...
Cart and Pole is a classical model in control laboratories for testing control algorithm. Balanci... more Cart and Pole is a classical model in control laboratories for testing control algorithm. Balancing control at equilibrium point has been operated many times on this model. However, a control algorithm that makes the system track a suggested trajectory, when stability requirement is guaranteed by mathematics, is still opened. In this paper, the author suggests using a sliding mode control to stabilize cart and pole system at an equilibrium point. Then, this algorithm controls the cart to track the trajectory of sine signal and pulse signal when still stabilizing pendulum on inverted position. On Matlab/Simulink simulation, sliding mode control proves its advantages over LQR control. Then, experiments show the abilities of applying sliding control for the real model.
The paper treats the control problem of the locomotion phases in a jumping cycle of a robot. The ... more The paper treats the control problem of the locomotion phases in a jumping cycle of a robot. The mechanical architecture of the leg with elastic lower segment (ATHLETE MODEL) is discussed. The dynamic model of the motion in stance phase is determined. The touch-down sequence, when the elastic foot hits the ground, is discussed and the control system is analyzed for two cases: actuator as passive damper system and actuator as semi-active damper system with ground-hook damper model. The transmissibility characteristics are analyzed. An active damper with ER fluids actuator and a skyhook viscosity controller is proposed to avoid the vibrations in the mechanical structure that can disturb the evolution of the robot. The control parameters are determined by using the circle criterion. The take-off sequence conditions in the stance phase are inferred by using the energy concept.
The paper presents an extension of the Circle Criterion for the dynamic models of the continuum r... more The paper presents an extension of the Circle Criterion for the dynamic models of the continuum robots. This technique is applied to the control of the fractional order model system with constraints of the driving forces. It is demonstrated that the stability of the closed loop control system requires that the arm frequency plot does not intersect the circle of driving constraints. It is shown that nonlinear components worsen the stability of the system. The proposed methods are illustrated by numerical simulation and experimental tests.
The team of Mechatronics and Robotics Department from the University of Craiova, Romania has a go... more The team of Mechatronics and Robotics Department from the University of Craiova, Romania has a good experience in higher academic activities, both teaching and research, connected with national and international projects. An important number of papers were published regarding educational policies, modern teaching methods, higher education quality system, and young researchers involving in multidisciplinary teams. This paper proposes a connected subject: The involvement of students with special needs in research activities, both as young researchers and as subject of the research activities.
Advances in Intelligent Systems and Computing, 2015
This paper presents a new hyper-redundant robotic arm structure and its sensorial, driving and co... more This paper presents a new hyper-redundant robotic arm structure and its sensorial, driving and control systems. A system of cables actuated by DC motors is used for bending. The position of the robot can be obtained by bending it with the cables and by blocking the position of the needed elements using an electro pneumatic system. The major advantage of this type of actuator consists in the fact that the robot can be moved using a boundary control by cables with a single actuating unit, the position blocking system for any element being relatively simple. The main features and advantages of the sensorial system and global robot system are presented. The dynamic model of the arm is developed using Lagrange’s formalism; the motion control system is based on the adaptive computed-torque method. Finally, experimental results are described.
2014 18th International Conference on System Theory, Control and Computing (ICSTCC), 2014
The curvature control problem for a class of hyper-redundant robot arms with continuum elements c... more The curvature control problem for a class of hyper-redundant robot arms with continuum elements characterized by an elastic backbone system is analyzed. The main parameters of the arm shape as curvature and curvature gradient are estimated. The stability analysis and the resulting controllers are obtained using the concept of boundary geometric control and a weighted state control methods. The proposed algorithm determines the control solutions using the dynamic model expressed in terms of curvature parameters. The objective of this paper is the curvature control problem of a tentacle arm with continuum elements HHR 02 (Hybrid Hyper-redundant Robot 02). Numerical simulations illustrate the effectiveness of the presented algorithms and techniques.
2013 17th International Conference on System Theory, Control and Computing (ICSTCC), 2013
This paper presents the structure of a backbone hyper-redundant arm with an electro-pneumatically... more This paper presents the structure of a backbone hyper-redundant arm with an electro-pneumatically system for position control. A system of cables actuated by DC motors is used for bending. Control system is based on a PIC microcontroller. The position of the robot can be obtained by bending it with the cables and by blocking the position of the elements we need, using the electro-pneumatically system. The major advantage of this type of actuation consists in the fact that the robot can be actuated using a boundary control by cables, the position blocking system for any element being relatively simple. The actuating system and the PIC microcontroller system is described and the main features of the global system are presented. The advantages of this robot architecture are discussed.
2014 18th International Conference on System Theory, Control and Computing (ICSTCC), 2014
This paper presents the sensorial system for structure of a backbone hyper-redundant arm with an ... more This paper presents the sensorial system for structure of a backbone hyper-redundant arm with an electro-pneumatically system for position control. A system of cables actuated by DC motors is used for bending. Control system is based on a PIC microcontroller. The position of the robot can be obtained by bending it with the cables and by blocking the position of the elements we need, using the electro-pneumatically system. The major advantage of this type of actuation consists in the fact that the robot can be actuated using a boundary control by cables, the position blocking system for any element being relatively simple. The sensorial system is described and the main features of the global system are presented. The advantages of this sensorial system for this robot architecture are discussed.
This paper is a component of a research project regarding the design and development of an Intell... more This paper is a component of a research project regarding the design and development of an Intelligent Haptic Robot-Glove for the rehabilitation of the patients that have a diagnosis of a cerebrovascular accident. In this paper, the control system for a rehabilitation hand exoskeleton is discussed. In order to avoid the complex problems given by a distributed sensor network, this paper treats the problem of the compliance force control by using observers: a velocity observer, a force observer and a disturbance observer. Two control solutions are discussed. First, the disturbance effects are eliminated by a cascade closed loop control with velocity and force observers. Then, a disturbance observer is used to compensate the compliance effects. The performance of the control systems is demonstrated by the simulation.
2013 19th International Conference on Control Systems and Computer Science, 2013
ABSTRACT This paper is based on the results of a research project regarding the design and develo... more ABSTRACT This paper is based on the results of a research project regarding the design and development of an Intelligent Haptic Robot-Glove (IHRG) for the rehabilitation of the patients that have a diagnosis of a cerebrovascular accident. The IHRG is an exoskeleton that supports the human hand and hand activities by using a control architecture for dexterous grasping and manipulation. The five-fingered assistive robotic glove is designed with mechanical compliance of human finger. The biomechanical elements of the exoskeleton assistive hand are designed considering: motion in different planes, adapted to patient's hand, possible to train pinch and grasp, opening/closing game. The actuation system is also studied and designed. The paper provides an overview of hand rehabilitation and evaluation techniques.
This paper studies the dynamic model of the continuum robots as a fractional order system. The vi... more This paper studies the dynamic model of the continuum robots as a fractional order system. The viscoelastic Kelvin-Voigt model is applied and a fractional order system is proposed and discussed. The distributed model is transformed in a nonlinear fractional order system by a weighting technique of the state variables. A control law defined with respect to direct observable variable, with a physical meaning, is proposed. A fractional order observer is proposed. The frequential criterions that ensure the asymptotical stability of the global model“observer-system“ are discussed. Numerical simulations and experimental results confirm the quality of the proposed algorithms.
In this paper is presented an experimental test stand of rheological stop-valves. Rheological sto... more In this paper is presented an experimental test stand of rheological stop-valves. Rheological stop-valve structures are robust, simple in terms of constructive and easy to control. However, due to non-Newtonian fluid flow rheological, are difficult to model mathematically. Since many parameters of these valves are determined empirically, and depend very much on the constructive parameters, it is necessary to determine them experimentally. The paper also presents a stand designed, developed and tested for magneto-rheological stop valves. This is shown schematically speaking, constructive and programming. The stand allows the experimental determination of parameters valves, their dependence on the type of fluid used and the type rheological field excitation applied to the fluid. Determination of valve parameters can be made for any type of field excitation. Applied voltage generator may be continuous, can be generated with a constant frequency or a frequency dictated by the law of ord...
The paper aims to study the applicability and limitations of the solution resulting from a design... more The paper aims to study the applicability and limitations of the solution resulting from a design process for an intelligent system supporting people with special needs who are not physically able to control a wheelchair using classical systems. The intelligent system uses information from smart sensors and offers a control system that replaces the use of a joystick. The necessary movements of the chair in the environment can be determined by an intelligent vision system analyzing the direction of the patient’s gaze and point of view, as well as the actions of the head. In this approach, an important task is to detect the destination target in the 3D workspace. This solution has been evaluated, outdoor and indoor, under different lighting conditions. In order to design the intelligent wheelchair, and because sometimes people with special needs also have specific problems with their optical system (e.g., strabismus, Nystagmus) the system was tested on different subjects, some of them...
2018 22nd International Conference on System Theory, Control and Computing (ICSTCC), 2018
Hyper-redundant robots of backbone types are generally driven by traction cables, making differen... more Hyper-redundant robots of backbone types are generally driven by traction cables, making different curves for different segments in their body. This paper presents the structure of a hyper-redundant robot of backbone type having an electro- rheologhic system for position control. For proper operation, so for bending, we uses a cables system with DC motor-driven. The control system is made with a PIC microcontroller. Modeling the robot's position is done by bending it with cables, combined with locking the desired elements position through the electro- rheological system. The major advantage of this type of drive lies in the fact that the robot modeling can be done with a system with only three cables, the position lock system of an element or segment is relatively simple. Also presented is a variable width signal system with constant amplitude where the duration of the input signal is the control variable. The control system uses a mixed control. We use this controller for contr...
2020 24th International Conference on System Theory, Control and Computing (ICSTCC), 2020
This paper focuses upon the detection of a tumor in one of the most common cancer in men, the pro... more This paper focuses upon the detection of a tumor in one of the most common cancer in men, the prostate cancer. The aim is to find out new methods to investigate this class of tumors, to identify the current state and their evolution. New algorithm to perform the prostate cancer cell analysis is proposed. The RGB color system of the cell is interpreted as a 3-D surface and the fractal analysis is performed. The Hölder exponents of this surface are investigated and the spectral analyze of the singularities is inferred. Spectral estimation is considered as one of the main factors that characterizes the surface irregularities. The granularity of the cells is investigated by the binary analysis of the grey image. An evaluation of the area of the light color subdomains is performed. A classification coefficient based on these two investigations is proposed.
In medicine, a prosthesis or prosthetic implant is an artificial device that replaces a missing p... more In medicine, a prosthesis or prosthetic implant is an artificial device that replaces a missing part of the body, which can be lost through trauma, disease, or illness present at birth. To help these amputated people, transtibial prostheses have been developed that have the role of increasing the motor abilities of the person in question. Among the different models of prostheses, the most frequently used are non-articulated prostheses, articulated prostheses, prostheses with energy re-turn/dynamic response, and microprocessor-controlled prostheses. The foot can vary the flexibility and elasticity of the complex structure to perform various challenging tasks, such as running, climbing, balancing, jumping, and lifting on the toes. To replace these functions, prostheses with different design and operating modes are used, depending on the activity performed. Thus, a person with social activity, or sports activity, requires the use of several prostheses with different modes of operation....
A heating and climatizer system based on selective absorption of solar energy by a selective coll... more A heating and climatizer system based on selective absorption of solar energy by a selective collector. The experimental study shows that the performance of this system depends on several variables: the nature of the colporteur fluid, the flow of the fluid circulation, the collector's surface area and the circulation mode (opened or closed circulation). The system was tested inside a building which contained a strawberry crop. A clear improvement of the performance has been achieved for an open circulation with appropriate working variables. The experimental results showed precocity of 14 days of the strawberry crop in comparison to a standard building. The variables of the experiment that can be controlled are: the flow of evacuated fluid, the entrance flow, the temperature of the fluid and the positioning of the transducer/ hole test. However, the measurement of these variables is affected by errors which cannot be completely eliminated.
The modularity of robotic subsystems is a big opportunity for robotics to compel recognition on t... more The modularity of robotic subsystems is a big opportunity for robotics to compel recognition on the market as a viable and efficient alternative, thanks to the development of standardized modulus, especially, but also because of the robots' features-such as productivity and flexibility. The idea of this proposal roots in the structure of a personal computer. The winding and the upgrade of a pc is an extremely simple and quick process thanks to the standardization of the functional modulus. Extrapolating this idea to robots, and to robotic systems, in general, it is necessary the conceiving of a modular system, as far back as in the primary design phase. The modular system should be conceived as intelligent structures with a high degree of sensorial, communicational, functional and control autonomy. These elements are presented and experimented with functional models, for validation. The conclusions are formulated and future directions are targeted.
2019 23rd International Conference on System Theory, Control and Computing (ICSTCC), 2019
Hyper-redundant robots are designed to work in space with restrictions. From the point of view of... more Hyper-redundant robots are designed to work in space with restrictions. From the point of view of the mobility of the discrete hyper-redundant robots, two constructive types are consecrated. With extreme mobility (element level actuating), a solution that requires actuators in each joint, to the detriment of weight and hence the length. With a large length (actuators in the base, and traction cables), a solution that increases the length of the robot against the mobility. In this paper, the authors propose a joint actuating solution that solves this problem. The proposed actuating system is a hybrid structure, based on pneumatic control with an electrorheological element. It made of a pneumatic actuation with kinematics and dynamics fully controllable based by a structure with an electrorheological stop valve. Also, the proposed electrorheological stop-valve solution reduces the limitations imposed on the fields of application of electro-rheological fluids, limitations due to the hi...
Cart and Pole is a classical model in control laboratories for testing control algorithm. Balanci... more Cart and Pole is a classical model in control laboratories for testing control algorithm. Balancing control at equilibrium point has been operated many times on this model. However, a control algorithm that makes the system track a suggested trajectory, when stability requirement is guaranteed by mathematics, is still opened. In this paper, the author suggests using a sliding mode control to stabilize cart and pole system at an equilibrium point. Then, this algorithm controls the cart to track the trajectory of sine signal and pulse signal when still stabilizing pendulum on inverted position. On Matlab/Simulink simulation, sliding mode control proves its advantages over LQR control. Then, experiments show the abilities of applying sliding control for the real model.
The paper treats the control problem of the locomotion phases in a jumping cycle of a robot. The ... more The paper treats the control problem of the locomotion phases in a jumping cycle of a robot. The mechanical architecture of the leg with elastic lower segment (ATHLETE MODEL) is discussed. The dynamic model of the motion in stance phase is determined. The touch-down sequence, when the elastic foot hits the ground, is discussed and the control system is analyzed for two cases: actuator as passive damper system and actuator as semi-active damper system with ground-hook damper model. The transmissibility characteristics are analyzed. An active damper with ER fluids actuator and a skyhook viscosity controller is proposed to avoid the vibrations in the mechanical structure that can disturb the evolution of the robot. The control parameters are determined by using the circle criterion. The take-off sequence conditions in the stance phase are inferred by using the energy concept.
The paper presents an extension of the Circle Criterion for the dynamic models of the continuum r... more The paper presents an extension of the Circle Criterion for the dynamic models of the continuum robots. This technique is applied to the control of the fractional order model system with constraints of the driving forces. It is demonstrated that the stability of the closed loop control system requires that the arm frequency plot does not intersect the circle of driving constraints. It is shown that nonlinear components worsen the stability of the system. The proposed methods are illustrated by numerical simulation and experimental tests.
The team of Mechatronics and Robotics Department from the University of Craiova, Romania has a go... more The team of Mechatronics and Robotics Department from the University of Craiova, Romania has a good experience in higher academic activities, both teaching and research, connected with national and international projects. An important number of papers were published regarding educational policies, modern teaching methods, higher education quality system, and young researchers involving in multidisciplinary teams. This paper proposes a connected subject: The involvement of students with special needs in research activities, both as young researchers and as subject of the research activities.
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Papers by Cristian Vladu