Prototype Robotic System Research Articles

Motion Planning Approach of a Multi-fingered Robot for Carton Folding Operation

The motion planning approach of a multi-fingered robot for carton flap folding operations has been newly developed. This approach considers the loci of the tool center point for carton flap folding operations. Also that considers the pushing or fixing points of the carton flap. This approach is calculated from the rotating angle for carton flap folding and the position of a robot finger tip in contact with the carton surface, using inverse kinematics. And this approach can be adapted to changes of a carton size or a folding position. When the carton flap is folded using this approach, the robot finger tip touches the carton surface without slipping and moves along circular continuous path. Therefore in case of the rectangular carton box folding, each robot finger moves in each 2.5-dimensional Cartesian frame. In this report, the proposed approach is verified using a prototype robot system. This system consists of two pairs of the robot fingers and rotating mechanism for carton paper. Each finger has a 3-DOF SCARA type robot and a 1-DOF linear motion system. The testing carton boxes can be folded to the desired shape.

Suction Control of a Robotic Gripper: A Neuro-Fuzzy Approach

This paper discusses a fuzzy logic control system designed to determine, regulate and maintain the amount of suction needed by a robotic gripper system to perform reliable limp material manipulation. A neuro-fuzzy approach is followed to determine the amount of desired suction (depending on experimentally derived data and plant characteristics). A knowledge-based valve controller is then designed to generate, regulate and maintain the amount of suction calculated by the neuro-fuzzy suction module. The performance of the overall suction control system is compared with actual experimental results obtained when using a prototype gripper system to handle limp material. Further, performance of the fuzzy logic based valve controller is compared to conventional PD and PID controllers. The proposed control scheme is found to enhance the overall functionality of the prototype robotic gripper system.

Robotic weed control system for tomatoes

A real-time intelligent robotic weed control system was developed for selective herbicide application to in-row weeds using machine vision and precision chemical application. The image processing algorithm took 0.34s to process one image containing 10 plant objects, representing a 11.43 cm by 10.16 cm region of seedline, and allowing the prototype robotic weed control system to travel at a continuous rate of 1.20 km/h. In actual field trials conducted in a commercial processing tomato field, the robotic weed control system correctly identified and didn't spray 75.8% of the tomato plants and correctly sprayed 47.6% of the weeds. The color segmentation look-up-tables made in hue, saturation, intensity color space were generally better than those made in normalized red, green, blue and un-normalized red, green, blue color spaces. Overall, look-up-tables built only with hue gave the best performance, correctly classifying 77.8% of color pixels. In validation tests with 290 field images from 13 different commercial processing tomato fields, the image processing algorithm correctly identified 58.5%-80.7% of tomato cotyledons, 9.0%-21.2% of tomato true leaves, 8.9%-12.9% of tomato leaves that were curled, occluded, bug-eaten or partially hidden by the edge of the image, and 93.0%-95.5% of weeds using plant area, length to perimeter ratio, and occupational ratio. For separation of occluded plant leaves, 5 modifications to the watershed algorithm were investigated. The performance of opening, feature criteria, and combined opening and feature criteria modifications were better than others. The recognition of occluded tomato cotyledons and true leaves improved 33.3% and 41.1%, respectively, after the modified watershed algorithm was applied to occluded objects. The angle of tomato cotyledon orientation for some varieties changed at different times of day. The critical orientation angle for tomato cotyledon recognition was estimated as 27.5$\sp\circ$ with the vertical axis of the plant. Spray trials with 2.54 cm and 1.27 cm diameter targets showed that the robotic spraying system correctly sprayed these simulated "weeds", targeting their centers within an average spatial error of 0.51-1.36 cm and a standard deviation of 0.21-.71 cm on three different ground surfaces.

Towards an automated approach for protein identification in proteome projects.

The development of automated, high throughput technologies for the rapid identification of proteins is essential for large-scale proteome projects. While a degree of automation already exists in some stages of the protein identification process, such as automated acquisition of matrix assisted laser desorption ionisation-time of flight (MALDI-TOF) mass spectra, efficient interfaces between different stages are still lacking. We report the development of a highly automated, integrated system for large scale identification of proteins separated by two-dimensional gel electrophoresis (2-DE), based on peptide mass fingerprinting. A prototype robotic system was used to image and excise 288 protein spots from an amido black stained polyvinylidene difluoride (PVDF) blot. Protein samples were enzymatically digested with a commercial automated liquid handling system. MALDI-TOF mass spectrometry was used to acquire mass spectra automatically, and the data analysed with novel automated peptide mass fingerprinting database interrogation software. Using this highly automated system, we were able to identify 95 proteins on the basis of peptide mass fingerprinting, isoelectric point and molecular weight, in a period of less than ten working days. Advantages, problems, and future developments in robotic excision systems, liquid handling, and automated database interrogation software are discussed.

Design and control of a mobile micromanipulator driven by ultrasonic motors with multidegrees of freedom

A miniature mobile micromanipulator system for performing submillimeter grasping and manipulation tasks has been designed and tested. The system consists of a two-fingered gripper attached to a 5 d.o.f. robot micromanipulator. Features of the system include: (i) the structure of the mobile micromanipulator is composed of high-precision ultrasonic actuators with several degrees of freedom (d.o.f.) (this makes the robot system easy to integrate and allows it to perform directed and precise translation motion or rotation in a plane or in space); (ii) the electronic drivers, based on a bidimensional PWM control architecture, allows us to command the multidirectional manipulator movement accurately, and, through them, to control the position and orientation of the gripper; and (iii) the gripper is actuated by a shape memory alloy actuator and employs strain gage sensors to perform the gripping force control. The prototype version of this mobile micromanipulator can perform micrometer movements with speeds in the range of few mm/s to several 10-1 m/s and manipulates objects in the size range of 2-0.5 mm. The design of the micromanipulator affords plenty of scope for further miniaturization. With the recent increased interest that has been shown in micro-robotics, the prototype robot system described in this paper could, with further development and miniaturization, form part of a micro-robot assembly system.

A robotically assisted munition loading system

AbstractDue to the reliance upon manual operations, conventional loading of munitions on tactical arcraft has several deficiencies including inefficient manpower and time utilization; accident potential; exposure of crew members to chemical, biological, and nuclear agents; and visual obstruction. This article reports on the research and development of a full‐scale prototype robotic system called Robotically Assisted Munition Loading System (RAMLS) comprising a fine motion mechanism (FIMOM), a pose acquisition device (PAD), a manual controller, and a data acquisition and computing system. The FIMOM is a six‐degree‐of‐freedom (DOF) parallel mechanism driven by six hydraulic actuators and the PAD is a passive open kinematic chain mechanism having 6 DOF. The article describes the design and functions of the RAMLS components and presents results of experiments conducted to evaluate the RAMLS's performance. © 3995 John Wiley & Sons, Inc.

A robotic system for performing sub-millemetre grasping and manipulation tasks

A robotic system for performing sub-millimetre grasping and manipulation tasks has been designed and tested. The system consists of a two-fingered gripper attached to a six-degrees-of-freedom robotic manipulator. Features of the system include: (1) the structure of the manipulator contains six spring-tensioned tendons - this makes the manipulator easy to construct and allows it to collapse in a reversible manner when overloaded, (2) step-motor driven winches adjust the tendon lengths and through them control the position and orientation of the gripper, (3) the gripper is actuated by a shape memory alloy actuator and employs an optical sensor to measure finger separation. The prototype version of this manipulator can perform a minimum movement of less than 0.05 mm and manipulates objects in the size range 2 mm to 0.2 mm. The design of the robotic manipulator and gripper afford plenty of scope for further miniaturisation. With the recent increased interest that has been shown in microrobotics there will be a need for robotic systems capable of assembling and manipulating microcomponents. The prototype robotic system described in this paper could, with further development and refinement, form part of a microrobot assembly system.

A system for robot manipulation of electrical wires using vision

SUMMARYA prototype robot system for automated handling of flexible electrical wires of variable length is described. The handling process involves the selection of a single wire from a tray of many, grasping the wire close to its end with a robot manipulator, and either placing the end in a crimping press or, for tinning applications, dipping the end in a bath of molten solder. This system relies exclusively on the use of vision to identify the position and orientation of the wires prior to their being grasped by the robot end-effector. Two distinct vision algorithms are presented. The first approach utilises binary imaging techniques and involves object segmentation by thresholding followed by thinning and image analysis. An alternative general-purpose approach, based on more robust grey-scale processing techniques, is also described. This approach relies in the analysis of object boundaries generated using a dynamic contour-following algorithm. A simple Robot Control Language (RCL) is described which facilitates robot control in a Cartesian frame of reference and object description using frames (homogeneous transformations). The integration of this language with the robot vision system is detailed, and, in particular, a camera model which compensates for both photometric distortion and manipulator inaccuracies is presented. The system has been implemented using conventional computer architectures; average sensing cycle times of two and six seconds have been achieved for the grey-scale and binary vision algorithms, respectively.

RIPS: a platform for experimental real-time sensory-based robot control

The design and performance benchmarking of the prototype robotic instruction processing systems (RIPS) at the Center for Robotic Systems in Microelectronics at the University of California-Santa Barbara, is discussed. The architecture of RIPS is specifically geared for robot control, yet the system is general and fully programmable and does not assume any manipulator characteristics. RIPS provides sufficient computing capacity to attack important real-time sensory-based robot control problems. Compliant control, multiple manipulator coordination, and manufacturing cell-level integration are presently under study. Experimental testing in these areas is possible because of RIPS' high computational performance for robot control problems: a Stanford manipulator using the computed torque method can be controlled with an update time of 255 mu s. This time includes inverse kinematics, dynamic compensation, and proportional derivative servoing for the six-degrees-of-freedom manipulator.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Design Issues in the Use of Robots as Cognitive Enhancement Aids

Abstract Robotic manipulators are being used in an investigation of their potential as effective classroom learning aids when used by severely orthopaedically disabled children to manipulate educational materials and to play games. During the course of the design and development of a prototype robotic system for educational use, several issues have surfaced that constitute serious considerations in the process. Of particular importance are issues involving accessibility, software design, curriculum integration and specific research questions involving spatial visualisation. Performance data from previous investigations has shown that learning to use robots can be easily accomplished, and that the consequent learning is remarkably resistant to decay over time.