High-performance Robot Research Articles

PERFORMANCE ANALYSIS OF GESTURE CONTROLLED ROBOTIC CAR

ROBOT” is any automatically operated machine or a device that reduces human effort, though it may not look much like a human being or function in a humanlike manner. Advanced, high-performance robots are used today in automobile manufacturing and aircraft assembly, and electronics firms use robotic devices together with other computerized instruments to sort or test finished products. Due to the demand of intelligent systems in every field of technology, automated systems are preferred much for the betterment of the society.The main objective of designing this robo car is to make the world work with more comfort and more easier way with the way they use today ,as in the recent era there were too many research in the field of robotics and communication has happened ,so we tried to focus both robotics as by designing a small robocar and controlling over RF frequency wirelessly for communication as the ease of access is our main priority we tried to focus also the comfort ability and design a gesture based robotic car. This car not only detects the motion of a human hand but also reacts according to the gesture, the main purpose of the bot is to make the world work with more ease or where the work of precision or accuracy is needed it can also be used for the spying and for the field observation or in the industries where the work precision is made with the use of human hand but it’s not comfortable due to hazardous object, we can have example of industries where furnace temperature or a pressure is controlled through the accuracy of a knob controlled with human hand but working beside the boiler or a furnace is always a risk task hence it is not possible so can be operated through gesture at a distance and operated can operate knob by simply sitting in the cabin and through gesture of the handjust like virtually adjusting the knob or the control of the robotic car.

Multiple-Degree-of-Freedom Counterbalance Robot Arm Based on Slider-Crank Mechanism and Bevel Gear Units

Low-cost but high-performance robot arms are required for robot arms to come into widespread use. To provide sufficient torques to support the robot mass and payload, most arms use expensive motors and speed reducers, which are the main reasons for their high price. As a solution to these problems, a multiple-degree-of-freedom (DOF) counterbalance mechanism and robot arm were developed in our previous study, which can compensate for the gravitational torque due to the robot mass. However, there are durability and reliability problems associated with wire-based mechanisms. To solve these, in this study, we proposed a new counterbalance mechanism based on a spring and slider-crank mechanism, along with a double-parallelogram mechanism composed of bevel gear units. Moreover, a 6-DOF counterbalance robot arm was built to verify the performance of the proposed mechanism. Simulation and experimental results showed that the proposed mechanism effectively decreased the torque required to support the robot mass, thus allowing the prospective use of low-cost motors and speed reducers for high-performance robots.

Torque Estimation for Robotic Joint With Harmonic Drive Transmission Based on Position Measurements

Joint torque sensory feedback is an effective technique for achieving high-performance robot force and motion control. However, most robots are not equipped with joint torque sensors, and it is difficult to add them without changing the joint's mechanical structure. A method for estimating joint torque that exploits the existing structural elasticity of robotic joints with harmonic drive transmission is proposed in this paper. In the presented joint torque estimation method, motor-side and link-side position measurements along with a proposed harmonic drive compliance model, are used to realize stiff and sensitive joint torque estimation, without the need for adding an additional elastic body and using strain gauges to measure the joint torque. The proposed method has been experimentally studied and its performance is compared with measurements of a commercial torque sensor. The results have attested the effectiveness of the proposed torque estimation method.

Multi-DOF Counterbalance Mechanism for a Service Robot Arm

Low-cost but high-performance robot arms are required for widespread use of service robots. Most robot arms use expensive motors and speed reducers to provide torques sufficient to support the robot mass and payload. If the gravitational torques due to the robot mass, which is usually much greater than the payload, can be compensated for by some means; the robot would need much smaller torques, which can be delivered by cheap actuator modules. To this end, we propose a novel counterbalance mechanism which can completely counterbalance the gravitational torques due to the robot mass. Since most 6-DOF robots have three pitch joints, which are subject to gravitational torques, we propose a 3-DOF counterbalance mechanism based on the double parallelogram mechanism, in which reference planes are provided to each joint for proper counterbalancing. A 5-DOF counterbalance robot arm was built to demonstrate the performance of the proposed mechanism. Simulation and experimental results showed that the proposed mechanism had effectively decreased the torque required to support the robot mass, thus allowing the prospective use of low-cost motors and speed reducers for high-performance robot arms.

Design and control of robot manipulator with a distributed actuation mechanism

This paper presents a design methodology based on the distributed actuation principle to achieve a high-performance robot manipulator. Spatial movement of the actuation points provides several advantages such as high payload capacity, high efficiency and a light weight structure for the proposed robot manipulator. Based on the analysis, the distributed actuation mechanism using a single slider is adopted for the proposed manipulator. A prototype of the manipulator with two degrees of freedom is developed and controlled as an example. The efficacy of the proposed approach is verified experimentally.

Selective approach towards robust control and accommodation of disturbances

Precision control is desirable in high performance robotics and automation systems. However, when extraneous disturbances step in, persistence with a precision control methodology can result in an unacceptable level of performance when the nominal conditions under which the nominal control is designed no longer hold. At this time, a suitable adaptive and robust control scheme would be useful to cope with the evolving situation with disturbances though it may not yield the same level of nominal control performance. Resolving these conflicting requirements in an appropriate and calculated manner during the course of operation of a motion system becomes an important issue to address to accommodate the disturbances and yield the best level of performance possible. In this paper, we present a selective approach towards commissioning a good compromise between nominal and appropriate robust adaptive control. The approach leverages on a sensor fusion method based on radial basis functions (RBFs) to provide a control selector signal indicative of the level of disturbance present to fire the appropriate control. Simulation results based on the model of a real linear motion system setup are provided to show the effectiveness of the approach.

Increasing Isotropy of Intrinsic Compliance in Robot Arms through Biarticular Structure

In human-robot interaction passive compliance is fundamental for safety, however stiffness is necessary for performance. These two factors motivate intrinsic compliance modulation in robots interacting with humans. Variable Stiffness Actuators (VSAs) allow for simultaneous position and stiffness control of a joint, therefore they have been implemented in the realization of intrinsically compliant and high performance robot arms. Most applications employ VSAs in a monoarticular structure, that is one actuator produces torque about one joint. In the biological world however, bi-articular muscles (muscles spanning two joints) play a fundamental role in motion control for humans, not only reducing link inertia, but also increasing isotropy of end effector force and compliance. In this work, a robot arm with VSAs and two interchangeable actuation structures (the traditional monoarticular and human-like biarticular) is built. The end effector intrinsic compliance in both the actuation structures is measured. Experimental results suggest that the biarticular VSA structure is more suitable for compliant robot arms.

W121005 トポロジー最適化技術を用いた高性能射出成形機用取出ロボットの開発

W121005 トポロジー最適化技術を用いた高性能射出成形機用取出ロボットの開発

High-Accuracy Positioning of an Industrial Robot Using Image/PSD-Based Hybrid Servo Control

This article presents a new and effective multi-sensor-based control strategy for high-accuracy/precision and high-efficiency automatic robot positioning in the field of industrial robot calibration. The strategy combines both coarsely visual servo and fine position-sensitive detector (PSD) servo control methods. In a large field of view, an image-based visual servo control system is employed to roughly guide the laser spot, which is from a single laser pointer attached to the end-effector of a robot to project to the segmented PSDs with a resolution of better than 0.1 µm. Once the laser spot is projected onto the active area of the PSD surface, the control will automatically be switched to the PSD feedback and servoing for fine positioning. An image/PSD-based servoing system has been presented. Based on the system, the controller design and switch logic of the hybrid servoing are given. The experimental results conducted on an ABB industrial robot IRB1600 verified the effectiveness of the developed visual/PSD hybrid servo controllers, as well as demonstrated that the high accuracy of 30 µm of robot positioning can be approached. The development of the hybrid control method and system has played a major role in achieving high-performance automatic robot calibration.

Optimal Task Placement of a Serial Robot Manipulator for Manipulability and Mechanical Power Optimization

Power consumption and accuracy are main aspects to be taken into account in the movement executed by high performance robots. The first aspect is important from the economical point of view, while the second is requested to satisfy technical specifications. Aiming at increasing the robot performance, a strategy that maximizes the manipulator accuracy and minimizes the mechanical power consumption is considered in this work. The end-effector is constrained to follow a predefined path during the optimal task positioning. The proposed strategy defines a relation between mechanical power and manipulability as a key element of the manipulator analysis, establishing a performance index for a rigid body transformation. This transformation is used to compute the optimal task positioning through the optimization of a multicriteria objective function. Numerical simulations regarding a serial robot manipulator demonstrate the viability of the proposed methodology.

高性能ロボット用総合プラットフォームＷＲ‐Ｘの開発

WR-X is an integrated platform for use in high-performance robots, making it possible to build simple, low-cost ultra-high-performance robots that can withstand the rigors of full-scale research use. Using WR-X makes it easy for anybody to build a wide variety of robots simply by combining modules as with a Lego construction set. To keep costs low and realize suitability to a wide range of uses, WR-X's actuator employs a standard over-the-counter RC servo used in radio-controlled models. Using an RC servo for a robot's actuator presents a wide range of difficulties. To overcome these, we developed specialized servo-control hardware to control the RC servo motor directly at a high level. This has made it possible to achieve an actuator with linear torque properties for use in ultra-high-performance robots, using a low-cost RC servo. Furthermore, we also developed an accelerator for conducting hardware-based image-analysis computation, in order to achieve real-time image analysis, which had been difficult with traditional small robots. This system has successfully computed the positions of eight physical objects on a screen in a mere 15.7[μs], achieving a speed increase to approximately 60,000 times the speed of software-based computation.

Catalytic water treatment process

This paper deals with the requirements, present development, and research issues concerning advanced material-handling systems based on programmable manipulators that are commonly called industrial robots.Industrial robots are becoming increasingly important as part of programmable automation systems being developed for the production of batch-produced discrete part goods. As contrasted with hard or fixed automation, programmable systems are designed for flexibility, that is, for ease of set-up for new or changing products in small or variable lot sizes, and adaptively responsive to a variable environment.Material handling entails the controlled manipulation of raw materials, workpieces, assemblies and finished products. Together with inspection and assembly, these functions represent essential parts of the total manufacturing process that are still highly labor-intensive.The great majority of present industrial robots (first generation) are performing relatively simple repetitive material handling tasks in highly constrained or structured environments. They are also increasingly used in spot-welding and paint-spraying operations. Second generation robots which incorporate computer processors or minicomputers have begun to appear in factories, considerably extending rudimentary pick-and-place operations. More advanced robots are being developed which incorporate visual and tactile sensing, all under computer control. These integrated systems begin to emulate human capabilities in coping with relatively unstructured environments.There are two major requirements for advanced material handling systems. The first requirement is for a programmed robot to be able to acquire randomly-positioned and un-oriented workpieces, subassemblies or assemblies from stationery bins or from moving conveyors, in a predetermined manner, and to convey them via a predetermined path, safely, to some desired position and orientation.The second requirement is for the robots to be able to place the acquired workpiece or assembly with a desired orientation in a position with a specified precision.These two requirements share the need for sensor-controlled manipulation to varying degrees. Tactile sensing may be sufficient for a simple task in which the workpieces are already oriented and require crude end-positioning at the destination such as in a palletizing operation. Visual sensing may be required when the workpieces are unoriented originally, are in motion, or when the final position is not precisely determined. In some instances, both tactile and visual sensing would be the most effective method, as when packing an unoriented container with workpieces in a desired order. Finally, in automated assembly processes, visual and/or tactile sensing may be required to bring parts together in fitting operations, or for insertions of shafts or bolts in holes. In the latter cases, the precision requirements for a passive accomodation system, together with the completeness of jigging or fixturing would govern how much sensor control was necessary.The major issues thus are the relative costs of orienting parts, of fixturing to preserve position and orientation, of high-performance robots (speed and precision) and on the trade-off attainable by the use of sensor control to reduce the cost of the other alternatives.

State space sampling of feasible motions for high-performance mobile robot navigation in complex environments

Sampling in the space of controls or actions is a well-established method for ensuring feasible local motion plans. However, as mobile robots advance in performance and competence in complex enviro...

Hardware design of high performance miniature anthropomorphic robots

Technical issues in designing reliable high-performance miniature humanoid robots are discussed. Although the light-weight and small-size body of such a humanoid robot facilitates safer and smoother experiments of agile motions involving large accelerations and impacts, building a complex humanoid system in a small body is still a challenging problem. Simultaneous requirements for wider motion ranges, higher rigidity, less fragile electric devices and circuits, and less sensitive electric wiring should be satisfied in a limited space. In order to meet them by overcoming the difficulties, we propose to mechanically modularize joint structures, and to equip a centralized electric control unit involving PC boards, sensing devices, signal-processors, communication boards, and power amplifiers. The developments of the mechanical modules and the centralized unit are made for two miniature humanoid robots.

DESIGN FOR HIGH DYNAMIC PERFORMANCE ROBOT BASED ON DYNAMICALLY COUPLED DRIVING AND JOINT STOPS

A new design approach is proposed for high dynamic performance robots, such as robots performing high-speed dynamic motions. This method is based on the utilization of dynamically coupled driving and joint stops. In the method, the dynamic performance index (DPI) formulated by the desired maximum motion specifications and the boundary conditions on initial/final configurations are combined to form a design index (DI) first. Then a dexterous mechanism consisting of very light actuators and links is initially designed under an assumption of utilizing dynamically coupled driving and joint stops. By increasing the load capabilities of the actuators step by step, an iterative process of searching for the solution of DI=0 with minimal torque needs is implemented to validate and improve the initial design. This process yields a robot that is lighter than conventional robots and capable of performing dynamic motions more efficiently by utilizing dynamically coupled driving and joint stops. Based on the method, a two-link golf swing robot performing high-speed swings is designed. Simulation results indicate the method can reduce the needs for the torque and power as compared with conventional design methods. The experiment clearly illustrates the merits of the method.

High-performance robotics and control may hold the key to future NASA missions, says Robotic Workspace Technologies, Inc.

High-performance robotics and control may hold the key to future NASA missions, says Robotic Workspace Technologies, Inc.

Modeling and Identification for High-Performance Robot Control: An RRR-Robotic Arm Case Study

This paper explains a procedure for getting models of robot kinematics and dynamics that are appropriate for robot control design. The procedure consists of the following steps: 1) derivation of robot kinematic and dynamic models and establishing correctness of their structures; 2) experimental estimation of the model parameters; 3) model validation; and 4) identification of the remaining robot dynamics, not covered with the derived model. We give particular attention to the design of identification experiments and to online reconstruction of state coordinates, as these strongly influence the quality of the estimation process. The importance of correct friction modeling and the estimation of friction parameters are illuminated. The models of robot kinematics and dynamics can be used in model-based nonlinear control. The remaining dynamics cannot be ignored if high-performance robot operation with adequate robustness is required. The complete procedure is demonstrated for a direct-drive robotic arm with three rotational joints.

New high-performance desktop robot offers large working area

New high-performance desktop robot offers large working area

Neural networks for advanced control of robot manipulators

Presents an approach and a systematic design methodology to adaptive motion control based on neural networks (NNs) for high-performance robot manipulators, for which stability conditions and performance evaluation are given. The neurocontroller includes a linear combination of a set of off-line trained NNs, and an update law of the linear combination coefficients to adjust robot dynamics and payload uncertain parameters. A procedure is presented to select the learning conditions for each NN in the bank. The proposed scheme, based on fixed NNs, is computationally more efficient than the case of using the learning capabilities of the neural network to be adapted, as that used in feedback architectures that need to propagate back control errors through the model to adjust the neurocontroller. A practical stability result for the neurocontrol system is given. That is, we prove that the control error converges asymptotically to a neighborhood of zero, whose size is evaluated and depends on the approximation error of the NN bank and the design parameters of the controller. In addition, a robust adaptive controller to NN learning errors is proposed, using a sign or saturation switching function in the control law, which leads to global asymptotic stability and zero convergence of control errors. Simulation results showing the practical feasibility and performance of the proposed approach to robotics are given.

Development of a High Precision Mounting Robot System With Fine Motion Mechanism(3rd Report). Positioning Experiments of SCARA Robot with Fine Mechanism.

In our previous work, robust control structure based on disturbance observer for a fast and precise fine motion mechanism has been proposed. The functionality of the controller was verified using one axis of precise X-Y table combined with-one axis fine motion mechanism. As a further step in this paper, the approach is extended to two-axes fine motion mechanism with a SCARA robot as a real system to realize the final purpose, that is, the development of high-precision mounting robot. First, the paper introduces a high performance robot system based on a SCARA robot coupled with a fine motion mechanism which was developed in our laboratory. Second, the paper presents a control scheme that enables correction of possible offsets of the end-effector relative to the target and compensation of the oscillations at the end-point. Finally, experimental results show significant improvements in end-point accuracy and settling time achieved by the novel configuration of the coarse/fine robotic system. As a result, a repeatability (3σ) less than 2 μm and the CP positioning error (3σ) less than 4.0 μm were achieved by the coarse/fine robotic system.