The synthesis of visual recognition strategies

Journal ArticleA coherent automated manufacturing system needs to include CAD/CAM, computer vision, and object manipulation. Currently, most systems which support CAD/CAM do not provide for vision or manipulation and similarly, vision and manipulation systems incorporate no explicit relation to CAD/ CAM models. CAD/CAM systems have emerged which allow the designer to conceive and model an object and automatically manufacture the object to the prescribed specifications. If recognition or manipulation is to be performed, existing vision systems rely on models generated in an ad hoc manner for the vision or recognition process. Although both Vision and CAD/CAM systems rely on models of the objects involved, different modeling schemes are used in each case. A more unified system will allow vision models to be generated from the CAD database. The model generation should be guided by the class of object being constructed, the constraints of the vision algorithms used and the constraints imposed by the robotic workcell environment (fixtures, sensors, manipulators and effectors). We are implementing a framework in which objects are designed using an existing CAGD system and recognition strategies (logical sensor specifications) are automatically synthesized and used for visual recognition and manipulation

Postprocesamiento CAM-ROBOTICA orientado al prototipado y mecanizado en células robotizadas complejas

The main interest of this thesis consists of the study and implementation of postprocessors to adapt the toolpath generated by a Computer Aided Manufacturing (CAM) system to a complex robotic workcell of eight joints, devoted to the rapid prototyping of 3D CAD-defined products. It consists of a 6R industrial manipulator mounted on a linear track and synchronized with a rotary table. To accomplish this main objective, previous work is required. Each task carried out entails a methodology, objective and partial results that complement each other, namely: - It is described the architecture of the workcell in depth, at both displacement and joint-rate levels, for both direct and inverse resolutions. The conditioning of the Jacobian matrix is described as kinetostatic performance index to evaluate the vicinity to singular postures. These ones are analysed from a geometric point of view. - Prior to any machining, the additional external joints require a calibration done in situ, usually in an industrial environment. A novel Non-contact Planar Constraint Calibration method is developed to estimate the external joints configuration parameters by means of a laser displacement sensor. - A first control is originally done by means of a fuzzy inference engine at the displacement level, which is integrated within the postprocessor of the CAM software. - Several Redundancy Resolution Schemes (RRS) at the joint-rate level are compared for the configuration of the postprocessor, dealing not only with the additional joints (intrinsic redundancy) but also with the redundancy due to the symmetry on the milling tool (functional redundancy). - The use of these schemes is optimized by adjusting two performance criterion vectors related to both singularity avoidance and maintenance of a preferred reference posture, as secondary tasks to be done during the path tracking. Two innovative fuzzy inference engines actively adjust the weight of each joint in these tasks.Andrés De La Esperanza, FJ. (2011). Postprocesamiento CAM-ROBOTICA orientado al prototipado y mecanizado en células robotizadas complejas [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/10627Palanci

"State-based Control Language a State-based, Interrupt-driven, Concurrent Language with Error Detection and Recovery"

A programming environment to support interactive, concurrent programming for Miarni University's Flexible Manufacturing System is described. The environment is intended to replace the existing extended cell programming language (ECPL), which was sequential in nature, to a state-driven one in order to support concurrency. The system has been altered from being sequential to reactive and is interrupt driven. This also enhances error detection and recovery capabilities. This paper will address the topics of Flexible Manufacturing Systems (FMS) and programming languages for manufacturing control, and will then develop a criteria for analyzing a FMS programming language. Based on that criteria, the former ECPL language will be discussed and analyzed to address problems in ECPL. The paper will conclude with an analysis of the new system outlining areas for further investigation and improvement

Research And Development Of Industrial Integrated Robotic Workcell And Robotrun Software For Academic Curriculum

Robotic automation is consuming the laborious tasks performed by workers all over industry. The increasing demand for trained robotic engineers to implement and maintain industrial robots has led to the development of various courses in academia. Michigan Tech is a FANUC Authorized Certified Education Training Center for industrial robot training. This report discusses the research and development of an integrated robotic workcell consisting of three Fanuc robots, Allen Bradley programmable logic controller (PLC), Mini-Mover belt conveyor and Fanuc iR-vision system. The workcell allows students to explore an environment similar to industry and intended to be used for laboratory hands-on activities in two robotic courses: Real-time Robotic Systems and Industrial Robotic Vision System. To complement hands-on activities and to meet the need of educating robotics to those without access to physical robots, an open source robotic simulation software RobotRun has been created in collaboration with a faculty member and students from Computer Science department. The features and a few training examples on the software have also been presented

Implementation and testing of a CAM postprocessor for an industrial redundant workcell with evaluation of several fuzzified Redundancy Resolution Schemes

This paper describes the implementation of a postprocessor to adapt the toolpath generated by a CAM system (NXTM) to a complex workcell of eight joints (namely, a KUKA KR15/2 manipulator mounted on a linear track and synchronized with a rotary table), devoted to the rapid prototyping of 3D CAD-defined products. Previously, it evaluates several Redundancy Resolution Schemes at the joint-rate level for the configuration of the postprocessor, dealing not only with the additional joints but also with the redundancy due to the symmetry on the milling tool. The use of these redundancies is optimized by adjusting two performance criterion vectors related to both singularity avoidance and maintenance of a preferred reference posture, as secondary tasks to be done during the path tracking. In addition, two proper fuzzy inference engines actively adjust the weight of each joint in these tasks. The postprocessor is validated in a real prototyping of a Valencian Falla.This research is partially supported by the Technical University of Valencia (PAID-00-09), project PROMETEO 2009/063 of Generalitat Valenciana and research project DPI2009-14744-C03-01 of the Spanish Government.Andrés De La Esperanza, FJ.; Gracia Calandin, LI.; Tornero Montserrat, J. (2012). Implementation and testing of a CAM postprocessor for an industrial redundant workcell with evaluation of several fuzzified Redundancy Resolution Schemes. Robotics and Computer-Integrated Manufacturing. 28(2):265-274. https://doi.org/10.1016/j.rcim.2011.09.008S26527428

Cell Programming Language Investigation of Extensions For Flow Control and Error Recovery in the Language

The Cell Programming Language (CPL) is a simple programming language which allows the students and faculty to easily program a workcell on a personal computer as the workcell controller. However, the original version of CPL lacks programming flexibility and power since it does not support subroutines, flow control, error recovery and operator interface to the execution of a CPL program. The objective of the project is to design and implement a new version of CPL to overcome the shortcomings of the original CPL by extending the language to include flow control, error recovery and operator interface to the execution of a CPL program. In this report CPL is introduced. The problems in the original CPL are addressed, the extensions to the original CPL are defined, and the implementation of the extensions is described. Some future development tasks are also discussed

PCLIPS

CLIPS is an expert system, created specifically to allow rapid implementation of an expert system. CLIPS is written in C, and thus needs a very small amount of memory to run. Parallel CLIPS (PCLIPS) is an extension to CLIPS which is intended to be used in situations where a group of expert systems are expected to run simultaneously and occasionally communicate with each other on an integrated network. PCLIPS is a coarse-grained data distribution system. Its main goal is to take information in one knowledge base and distribute it to other knowledge bases so that all the executing expert systems are able to use that knowledge to solve their disparate problems

Vibration control on linear robots with digital servocompensator

Control application for active damping of structural vibrations and acoustic noise in mechanical systems is one of the engineering fields that can benefit from advances made in digital signal processors. This thesis project is one such application. It is about a vibration control at the loading point of a high speed linear robotic workcell. A lead zirconate titanate piezoelectric ceramic is used as the actuator and an accelerometer provides the sensing. From experimentally measured frequency response of this system, a shaping filter is designed and added on. The reshaped system is fitted with a third order transfer function design model. And based on this model, a discrete-time control scheme designated “servocompensator” is designed and implemented on a Digital Signal Processing board to control structural vibrations on the robotic workcell. Servocompensator is a control scheme based on the principle of Internal Model Design. The results have demonstrated the servocompensator as a powerful scheme for controlling independently the individual modes within the spectrum of a given vibration signal. In a typical result, as much as 40 dB of attenuation is produced on the targeted mode, where 0 dB is equal to 1 g of acceleration in this application. Furthermore, with the multi-tasking capability of the digital hardware, multiple mode control is demonstrated by multiplexing a number of single-mode servocompensators