Degree Of Freedom Robotic Arm Research Articles

1P1-P01 トルク計測と外力計測によるロボットアームの力学パラメータの同定(動作計画と制御の新展開(1))

This paper shows a comparison of joint based and contact-force based dynamics identification for a 5 degrees of freedom robotic arm. Off-line robot dynamic identification methods are mostly based on using Inverse Dynamics, which calculates the joint torque or contact-force that are linear in relation to dynamic parameters. The estimation of the parameters is carried out using a total least squares or weighted least squares method. However, these methods can identify only the minimal-set of inertial parameters. In this paper we calculate the dynamic parameters in two ways which are joint based and contact-force based and we also calculate the standard parameters closet to a priori consistent dynamic parameters obtained through CAD data given by the robot manufacturer. Then, we compare joint based and contact-force based identification method with experimental data.

ロボットアームの受動関節を利用した人の位置決め補助に関する研究

The present study proposes a robot arm that can support precise positioning in operation by a human. The robot arm has passive and actuated joints. The passive joint is not mechanically constrained and can move passively with the motion of the output point of the robot arm. Therefore, a human can move the output point of the robot arm by his will. When a human tries to move the output point along an object path, the displacement of the passive joint is determined passively. Then, if the actuated joint is controlled so that the output point may be on the object path, the human can achieve precise positioning. Namely, using the proposed robot arm, the human can adjust the velocity, acceleration, applied force and so on by his will, while the position is preciously compensated by the actuated joint. This paper describes a mechanical form of such robot arm for drawing of planar figures and shows that the robot arm has specific singularity condition. In order to avoid the singularity condition, the proposed robot arm interchanges the actuated joint and the passive one situationally. The study fabricated the two degrees of freedom robot arm for positioning assistance and described its control method. Furthermore, its availability is confirmed by drawing some figures.

Design, Modeling and Performance Testing of End-Effector for Sweet Pepper Harvesting Robot Hand

This paper presents a new design and modeling fundamentals of gripper and cutting system for 5 degree of freedom robotic arm, designed to harvest sweet peppers in horticultural green house. The design consists of two parallel jaws mounted on gears and operated with the help of servo motor. The same servo motor was used to operate the cutting system which was composed of scissors. The complete system was designed to operate by using one servo motor only. The system model was developed in SolidWorks and tested for different kinematic and dynamic performances. The performance of the gripper and cutting tool system has been evaluated through simulation to determine the design parameters of practical prototype. Based on the design concept, practical prototype of the gripper and cutting system was developed by considering the results obtained by model developed in SolidWorks. The developed prototype was tested to verify the feasibility and reliability of the model developed in Solid-Works. The performance and practical application of the developed prototype was verified and validated by conducting experiments in the lab and greenhouse and comparing the results with simulation results.

Four Degrees of Freedom Robot Arm, Low-Cost Competition in the Design and Development

The focus of this work is to design, develop and implement enhanced control and competitive robot arm thick and short cost. Design of four degree of freedom and talent of robot arm is to complete the accurate and simple tasks, such as optical materials processing, will be integrated into the mobile platform, as an assistant for the industrial labor force. Between the robot arm equipped with weapons and arm movements associated with the plurality of servo motor. Servo motor, encoder, so as to realize no controller includes. To control the robot, using Lab view, to the computation of the inverse kinematics of serial communication and proper angle, a micro controller, servo motor and drive ability of modify the location, velocity and acceleration. The robot arm was tested and verified, results show that, its normal work.

Identification of Two Degree of Freedom Robot Arm’s Joints’ Time-Varying Stiffness

This paper is concerned with the identification problem of two degree of freedom robot arm’s joints’ time-varying stiffness. The dynamic equation of two degrees of freedom robot arm can be obtained by using analytical mechanics method. Then by choosing limited memory least square method, time-varying stiffness can be identified. Finally, the calculative stiffness is compared to the “real” stiffness which is simulated in ADAMS. The whole process shows that the robot arm’s dynamic model and the method of identification are both effective.

Identification of robot arm’s joints’ time-varying stiffness under loads

This paper is concerned with the identification problem of two degree of freedom robot arm’s joints’ time-varying stiffness under time-varying torque loads. The industrial robot arms can be simplified into series hinged linkage mechanism. The unrestraint dynamic equation of two degrees of freedom robot arm can be obtained by using analytical mechanics method. The model which was established in Pro/E had been imported into ADAMS for simulation. And the simulation consisted of free vibration and forced vibration. Then by choosing limited memory least square method and using the post-processing measured variables, time-varying stiffness could have been identified. Finally, the calculative stiffness was compared to the “real” stiffness which was simulated in ADAMS. The whole process shows that the robot arm’s dynamic model and the method of identification are both effective. DOI: http://dx.doi.org/10.11591/telkomnika.v10i8.1644 Full Text: PDF

Off-line view planning for the inspection of mechanical parts

3D optical scanning systems are used more and more for quality control purposes. The effective utilization of such systems needs an efficient virtual planning of the product acquisition viewpoints. Literature shows how 3D CAD product models can be used as reference in order to manage the verification process and as a basis for the computation of the optimal viewpoints. However, in the mechanical field, a variety of inspection tasks is experienced by engineers involved in the quality control process: GD&T verification, production phases control such as sheet metal cutting, evaluation of aesthetic appearance of parts, global shape deformation measurement and specific point deviations assessment. This leads to the necessity of flexible view planning approaches which adapt to the specificity of the required inspection task. The present work targets the development of a comprehensive view planning approach in which several algorithmic options are triggered by the product features to be inspected. Algorithms have been implemented in a prototypal software system which has been experimented as an off-line application to provide inputs to a multi-axis degree of freedom robot arm mounting an optical 3D scanner. Two test cases from die casting and automotive fields are presented. They show the computation of acquisition poses in a suitable sequence and efficiency in the obtained results.

1A1-G02 Development of Thermal Cutting System for Sweet Pepper Harvesting Robot in Greenhouse Horticulture(Robotics and Mechatronics in Agriculture)

This paper proposes the new design of thermal cutting system for 5 degree of freedom robotic arm, designed to harvest sweet peppers in horticultural green house. The design consists of two parallel gripper bars mounted on a frame connected by specially designed notch plate and operated by servo motor. The special electric device was developed to obtain the high frequencies with high voltage to perform the cutting operation. The output from the device was connected to the electric rods mounted at the front of the specially designed notch plate. At higher frequencies, the rods generate thermal arc which helps to cut the stem of the sweet pepper. The recognition system assists to locate the fruit.

Autologous Osteochondral Transplantation of the Talus Partially Restores Contact Mechanics of the Ankle Joint

Background: Autologous osteochondral transplantation procedures provide hyaline cartilage to the site of cartilage repair. It remains unknown whether these procedures restore native contact mechanics of the ankle joint. Purpose: This study was undertaken to characterize the regional and local contact mechanics after autologous osteochondral transplantation of the talus. Study Design: Controlled laboratory study. Methods: Ten fresh-frozen cadaveric lower limb specimens were used for this study. Specimens were loaded using a 6 degrees of freedom robotic arm with 4.5 N·m of inversion and a 300-N axial compressive load in a neutral plantar/dorsiflexion. An osteochondral defect was created at the centromedial aspect of the talar dome and an autologous osteochondral graft from the ipsilateral knee was subsequently transplanted to the defect site. Regional contact mechanics were analyzed across the talar dome as a function of the defect and repair conditions and compared with those in the intact ankle. Local contact mechanics at the peripheral rim of the defect and at the graft site were also analyzed and compared with the intact condition. A 3-dimensional laser scanning system was used to determine the graft height differences relative to the native talus. Results: The creation of an osteochondral defect caused a significant decrease in force, mean pressure, and peak pressure on the medial region of the talus (P = .037). Implanting an osteochondral graft restored the force, mean pressure, and peak pressure on the medial region of the talus to intact levels (P = .05). The anterior portion of the graft carried less force, while mean and peak pressures were decreased relative to intact (P = .05). The mean difference in graft height relative to the surrounding host cartilage for the overall population was −0.2 ± 0.3 mm (range, −1.00 to 0.40 mm). Under these conditions, there was no correlation between height and pressure when the graft was sunken, flush, or proud. Conclusion/Clinical Relevance: Placement of the osteochondral graft in the most congruent position possible partially restored contact mechanics of the ankle joint. Persistent deficits in contact mechanics may be due to additional factors besides graft congruence, including structural differences in the donor cartilage when compared with the native tissue.

Hekateros: A Desktop 5 Degree-of-Freedom Robot Arm for the Small-Scale Manipulation Robot Chess Challenge

RoadNarrows has entered the “desktop-size” 5 degree of freedom robot arm, Hekateros, in the Small-Scale Manipulator Challenge, at the 2011 AAAI conference. Hekateros is utilizing a variety of sensors and software to successfully perceive and manipulate the chess gam

Understanding how children understand robots: Perceived animism in child–robot interaction

Centuries ago, the existence of life was explained by the presence of a soul ( Tylor, 1871). Known as animism, this term was re-defined in the 1970s by Piaget as young children's beliefs that inanimate objects are capable of actions and have life-like qualities. With the development of robots in the 21st century, researchers have begun examining whether animism is apparent in children's impressions of robots. The purpose of this study was to use a model of knowledge structures, or schemata, to examine whether children attribute human qualities of cognition, affect, and behavior to a robot. An experiment was set up at a science center located in a major Western Canadian city, and visitors to the center were invited to participate. A total of 198 children ages 5–16 years ( M=8.18 years) with an approximate even number of boys and girls were included. Children completed a semi-structured interview after observing a robot, a small 5 degree of freedom robot arm, perform a block stacking task. Answers to the nine questions about the robot were scored according to whether they referenced humanistic qualities. Results from frequency and content analyses suggest that a significant proportion of children ascribe cognitive, behavioral, and especially affective, characteristics to robots.

Closing the sensorimotor loop: haptic feedback facilitates decoding of motor imagery

The combination of brain–computer interfaces (BCIs) with robot-assisted physical therapy constitutes a promising approach to neurorehabilitation of patients with severe hemiparetic syndromes caused by cerebrovascular brain damage (e.g. stroke) and other neurological conditions. In such a scenario, a key aspect is how to reestablish the disrupted sensorimotor feedback loop. However, to date it is an open question how artificially closing the sensorimotor feedback loop influences the decoding performance of a BCI. In this paper, we answer this issue by studying six healthy subjects and two stroke patients. We present empirical evidence that haptic feedback, provided by a seven degrees of freedom robotic arm, facilitates online decoding of arm movement intention. The results support the feasibility of future rehabilitative treatments based on the combination of robot-assisted physical therapy with BCIs.

A Robot Arm for Assisting Liver Surgery

AbstractLiver surgery is a complex operation. During the operation, even with the help of realtime CT imaging, doctors often struggle in finding the exact tumor positions. This paper introduces a robot arm specially designed for assisting liver surgery. It includes a 5 DOF (Degree-of-Freedom) robot arm and a computer software system. The position resolution of the robot arm is 0.1mm and the software system is developed using Visual C++. The robot arm can hold an endoscope. With the help of electromagnetic position tracking device, the robot arm can also show the path of the endoscope during the surgery. To test the accuracy of the robot arm, a prototype is designed and built. The experiment results show that the position accuracy of the robot arm is 0.3mm, sufficient for assisting liver surgery. In addition, the cost of this system is only about US$10, 000, much lower than thesurgical robot systems in the market.

Would Children Help a Robot in Need?

Just as human-human behavior and interactions are important to study, human-robot interactions will take more prominence in the near future. These interactions will not only be in one direction, robots helping humans, but they will also be bidirectional with humans helping robots. This study examined the interactions between children and robots by observing whether children help a robot complete a task, and the contexts which elicited the most help. Five studies were conducted each consisting of 20 or more children per group with an approximate even number of boys and girls. Visitors to a science centre located in a major Western Canadian city were invited to participate in an experiment set up at the centre. Their behaviors with a robot, a small 5 degree of freedom robot arm programmed with a set of predefined tasks which could be selected during the experiments, were observed. Results of chi-square analyses indicated that children are most likely to help a robot after experiencing a positive introduction to it, X 2(1)=4.15,p=.04. Moreover, a positive introduction in combination with permission to help resulted in the vast majority (70%) of children helping. These results suggest that adult instructions about a robot impact children’s perceptions and helping behaviors towards it. The generalizability of these results to children’s helping behaviors towards people is also discussed.

Children’s relationships with robots: robot is child’s new friend

The purpose of this study was to examine how children think about and attribute features of friendship to a robot after a brief interaction with one. Children visiting a science centre located in a major Western Canadian city were randomly selected to participate in an experiment set up at the centre. A total of 184 children ages 5 to 16 years (M = 8.18 years) with an approximate even number of boys and girls participated. Children were interviewed after observing a traditional robot, a small 5 degree of freedom robot arm, perform a block stacking task. Content analysis was used to examine responses to nine open-ended questions. Results indicate that the majority of children were willing to engage in friendship with the robot by showing positive affiliation and social support towards it, as well as sharing activities, and communicating with it. Significant sex differences in how children ascribe characteristics of friendship to a robot were also found.

Adaptive Neuro-Fuzzy Inference System based control of six DOF robot manipulator

The dynamics of robot manipulators are highly nonlinear with strong couplings existing between joints and are frequently subjected to structured and unstructured uncertainties. Fuzzy Logic Controller can very well describe the desired system behavior with simple if-then relations owing the designer to derive if-then rules manually by trial and error. On the other hand, Neural Networks perform function approximation of a system but cannot interpret the solution obtained neither check if its solution is plausible. The two approaches are complementary. Combining them, Neural Networks will allow learning capability while Fuzzy-Logic will bring knowledge representation (Neuro-Fuzzy). This paper presents the control of six degrees of freedom robot arm (PUMA Robot) using Adaptive Neuro Fuzzy Inference System (ANFIS) based PD plus I controller. Numerical simulation using the dynamic model of six DOF robot arm shows the effectiveness of the approach in trajectory tracking problems. Comparative evaluation with respect to PID, Fuzzy PD+I controls are presented to validate the controller design. The results presented emphasize that a satisfactory tracking precision could be achieved using ANFIS controller than PID and Fuzzy PD+I controllers Abstract The dynamics of robot manipulators are highly nonlinear with strong couplings existing between joints and are frequently subjected to structured and unstructured uncertainties. Fuzzy Logic Controller can very well describe the desired system behavior with simple if-then relations owing the designer to derive if-then rules manually by trial and error. On the other hand, Neural Networks perform function approximation of a system but cannot interpret the solution obtained neither check if its solution is plausible. The two approaches are complementary. Combining them, Neural Networks will allow learning capability while Fuzzy-Logic will bring knowledge representation (Neuro-Fuzzy). This paper presents the control of six degrees of freedom robot arm (PUMA Robot) using Adaptive Neuro Fuzzy Inference System (ANFIS) based PD plus I controller. Numerical simulation using the dynamic model of six DOF robot arm shows the effectiveness of the approach in trajectory tracking problems. Comparative evaluation with respect to PID, Fuzzy PD+I controls are presented to validate the controller design. The results presented emphasize that a satisfactory tracking precision could be achieved using ANFIS controller than PID and Fuzzy PD+I controllers Abstract The dynamics of robot manipulators are highly nonlinear with strong couplings existing between joints and are frequently subjected to structured and unstructured uncertainties. Fuzzy Logic Controller can very well describe the desired system behavior with simple if-then relations owing the designer to derive if-then rules manually by trial and error. On the other hand, Neural Networks perform function approximation of a system but cannot interpret the solution obtained neither check if its solution is plausible. The two approaches are complementary. Combining them, Neural Networks will allow learning capability while Fuzzy-Logic will bring knowledge representation (Neuro-Fuzzy). This paper presents the control of six degrees of freedom robot arm (PUMA Robot) using Adaptive Neuro Fuzzy Inference System (ANFIS) based PD plus I controller. Numerical simulation using the dynamic model of six DOF robot arm shows the effectiveness of the approach in trajectory tracking problems. Comparative evaluation with respect to PID, Fuzzy PD+I controls are presented to validate the controller design. The results presented emphasize that a satisfactory tracking precision could be achieved using ANFIS controller than PID and Fuzzy PD+I controllers

Fuzzy PD+I control of a six DOF robot manipulator

PurposeThe purpose of this paper is to present the control of a six degrees of freedom (DOF) robot arm (PUMA robot) using fuzzy PD + I controller. Numerical simulation using the dynamic model of six DOF robot arm shows the effectiveness of the approach in trajectory tracking problems. Comparative evaluation with respect to PID and fuzzy PID controls are presented to validate the controller design. The results presented emphasize that a satisfactory tracking precision could be achieved using fuzzy PD + I controller combination than fuzzy PID controller.Design/methodology/approachControl of a six DOF robot arm (PUMA Robot) using fuzzy PD + I controller.FindingsThe performance of fuzzy PD + I controllers improves appreciably compared to their respective fuzzy PID only or conventional PID counterparts.Originality/valueComplexity of the proposed fuzzy PID controller is minimized as possible and only two design variables are used to adjust the rate of variations of the proportional gain and derivative gain.

Set up of an Automated Multi-Colour System for Interior Wall Painting

It is shared that construction projects are getting bigger and more complex, hence also the productivity of the construction industry must be improved, while preserving its labour from hazardous job sites. Such requirements can be accomplished by the adoption of robotized products, which, however, need to be quickly developed and marketed. In this paper, first the issue of a new miniature laboratory for developing lightweight and well-coordinated robotized systems is pursued, then a novel robot device for high quality multi-colour interior wall painting carried by a robot arm is developed and successfully tested. Thanks to the new 1:6 scaled down laboratory and its six degree of freedom robot arm on an hexapod for horizontal moves, we tested the opportunity to introduce also in the building sector miniature robots that can change the ergonomics standardly adopted by construction workers. It is analyzed how and why switching from full size to miniature robots is convenient in construction. In addition, a new system adding further features to robotized painting has been conceived. Our new multi-colour spraying end-tool was developed and fixed on the robot arm, in order to be able to reproduce coloured artworks. Finally, a methodology to reproduce colours from digital format of artworks is presented, showing how accurate and efficient is this new robotized spraying device.

A New Mechatronic Assistance System for the Neurosurgical Operating Theatre: Implementation, Assessment of Accuracy and Application Concepts

Objective: To introduce a new robotic system to the field of neurosurgery and report on a preliminary assessment of accuracy as well as on envisioned application concepts. Based on experience with another system (Evolution 1®, URS Inc., Schwerin, Germany), technical advancements are discussed. Material/Methods: The basic module is an industrial 6 degrees of freedom robotic arm with a modified control element. The system combines frameless stereotaxy, robotics, and endoscopy. The robotic reproducibility error and the overall error were evaluated. For accuracy testing CT markers were placed on a cadaveric head and pinpointed with the robot’s tool tip, both fully automated and telemanipulatory. Applicability in a clinical setting, user friendliness, safety and flexibility were assessed. Results: The new system is suitable for use in the neurosurgical operating theatre. Hard- and software are user-friendly and flexible. The mean reproducibility error was 0.052–0.062 mm, the mean overall error was 0.816 mm. The system is less cumbersome and much easier to use than the Evolution 1. Conclusions: With its user-friendly interface and reliable safety features, its high application accuracy and flexibility, the new system is a versatile robotic platform for various neurosurgical applications. Adaptations for different applications are currently being realized.

Use of a Novel Robotic System for Retrosigmoid Internal Auditory Canal Decompression

Introduction: (1) Determine whether a 7 degrees of freedom robotic arm can be useful for retrosigmoid (RS) acoustic neuroma resection; (2) understand the complexities of adapting robotics to skull base surgery.