Department Publications

Presents a general solution to the contouring problem of industrial robot arms, under the constraints of assigned Cartesian velocity and joint torque/acceleration. The proposed solution is an off-line trajectory generation algorithm and, therefore, it possesses significant industrial implications, as no hardware changes are needed for its implementation. According to the proposed method, the maximum utility of joint torque/acceleration is guaranteed to be bound to the assigned velocity constraint. In the proposed method, a realizable trajectory is generated from the objective trajectory and its delay dynamics are compensated for by using a forward compensator. The proposed method has been experimented with using a Performer MK-3s (PMK-3s) industrial robot arm, and optimum contouring has been realized.

Presents a control algorithm for industrial robot arms. This algorithm is based on off-line trajectory generation with compensation of statics and dynamics. Using the proposed method, the Performer MK-3s industrial robot arm was controlled and improved performance has been realized. The proposed algorithm appears as a feedforward, off-line block in the robot arm control system. Therefore, it could be conveniently incorporated with the industrial robot arms without significant hardware alterations.

This paper addresses the contouring problem of articulated industrial robot arms, and proposes a practical solution to realize precise, jerk-free servoing. The proposed solution is an off-line trajectory construction algorithm that addresses the relevant industrial constraints and specifications namely, the velocity constraint, torque/acceleration constraint and trajectory allowance. Spline approximation is used to eliminate jerking. A forward compensator is used to compensate for delay dynamics. The proposed method was implemented experimentally on a Performer Mk-3s industrial robot arm, and improved performances were demonstrated.

The paper describes several digital signal processing (DSP) techniques used in the development of a computer-based speech trainer for hearing impaired children. Children with congenital hearing impairments have difficulties in speaking, and even in making the basic sounds associated with speech. Speech therapists use specialized training methods to train such children. The dearth of qualified speech therapists, and other facilities hinder the speech development of many children in need of such training in Sri Lanka. The speech trainer described in this paper was developed as an alleviation to the above problem. The training tool developed, will aid a child with initial guidance from an adult, to master the pronunciation of initial sounds taught in a speech therapy programme, in a game-like environment. In its current status, the training tool can guide children in pronouncing the five vowel sounds, the first step in …

Visual Cue Selection, Substitution and Integration for Robust Object Tracking | CiNii Research CiNii 国立情報学研究所 学術情報ナビゲータ[サイニィ] 詳細へ移動 検索フォームへ 移動 論文・データをさがす 大学図書館の本をさがす English 検索 タイトル 人物/団体名 著者ID/研究 者番号 所属機関 ISSN DOI 期間 ~ 本文リンク 本文リンクあり データソース JaLC IRDB Crossref DataCite NDLサーチ NDLデジコレ(旧NII-ELS) RUDA JDCat NINJAL CiNii Articles CiNii Books NACSIS-CAT/ILL DBpedia KAKEN Integbio PubMed LSDB Archive 極地研ADS 極地 研学術DB OpenAIRE 公共データカタログ すべて 研究データ 論文 本 博士論文 プロジェクト 人物 > 人物検索機能について Visual Cue Selection, Substitution and Integration for Robust Object Tracking Web Site Web Site Web Site 参考文献48件 Ajith Pasqual 相澤 清晴 書誌事項 タイトル別名 Visual Cue Selection Substitution and Integration for Robust …

Pole selection for modified taught data method for mechatronic servo systems by considering bounded control | CiNii Research CiNii 国立情報学研究所 学術情報ナビゲータ[サイニィ] 詳細へ 移動 検索フォームへ移動 論文・データをさがす 大学図書館の本をさがす English 検索 タイトル 人物 /団体名 著者ID/研究者番号 所属機関 ISSN DOI 期間 ~ 本文リンク 本文リンクあり データソース JaLC IRDB Crossref DataCite NDLサーチ NDLデジコレ(旧NII-ELS) RUDA JDCat NINJAL CiNii Articles CiNii Books NACSIS-CAT/ILL DBpedia KAKEN Integbio PubMed LSDB Archive 極地研ADS 極地研学術DB OpenAIRE 公共データカタログ すべて 研究データ 論文 本 博士論文 プロジェクト 人物 > 人物検索機能について Pole selection for modified taught data method for mechatronic servo systems by considering bounded control 被引用文献1件 MUNASINGHE SR 収録刊行物 Proc. SICE Kyushu Branch Annual Conf, Kagoshima, Japan, 2001 Proc. SICE …

Contour control of a robot arm is an act of the end-effector tip being moved along a reference Cartesian path, with an assigned velocity. When torque saturation occurs, and lasts for some time, contour deteriorations result. In addition, system delay dynamics also causes contour deteriorations. In this paper, an offline trajectory generation algorithm is described, which achieves both optimum avoidance of torque saturation and delay dynamics compensation.

The performance of a coherent delay-locked tracking scheme for direct-sequence/spread-spectrum systems using half-sine or triangular chip waveforms for early and late despreading sequences is analyzed. The effect of band-limiting on the received signals is considered. Mean time to lose lock (MTLL) and root mean square (rms) tracking error of the delay-locked loop (DLL) are compared with that of a conventional DLL which uses rectangular chip despreading waveforms. Linear and nonlinear (based on the renewal process approach) analyses are employed to evaluate the performance of the DLL. Results show that the use of either the half-sine or triangular chip waveform reduces the rms tracking error and increases the MTLL considerably when the early-late spacing is approximately between 0.7-1.3 chip times. The results apply in particular to the commonly used DLL using one chip early-late spacing …

Feasible Method of Optimum Control of Industrial Robot Arms in Operation Under Speed and Torque Constraints | CiNii Research CiNii 国立情報学研究所 学術情報ナビゲータ[サイニィ ] 詳細へ移動 検索フォームへ移動 論文・データをさがす 大学図書館の本をさがす English 検索 タイトル 人物/団体名 所属機関 ISSN DOI 期間 ~ 本文リンク 本文リンクあり データソース JaLC IRDB Crossref DataCite NDLサーチ NDLデジコレ(旧NII-ELS) RUDA JDCat NINJAL CiNii Articles CiNii Books NACSIS-CAT/ILL DBpedia KAKEN Integbio PubMed LSDB Archive 極地 研ADS 極地研学術DB OpenAIRE 公共データカタログ すべて 研究データ 論文 本 博士論文 プロジェクト Feasible Method of Optimum Control of Industrial Robot Arms in Operation Under Speed and Torque Constraints 被引用文献1件 NAKAMURA M. 収録刊行物 3rd Asian Control Conference 3rd Asian Control Conference 2000 …

The design and implementation of a low cost bell and light protection system for a railway level crossing is described. This is directly targeted to cater for the un protected level crossings in Sri Lanka. The design is entirely hardware oriented. It detects the presence of a train on the rail track to activate a set of red lights and a bell to warn the road users. To enhance the reli ability of the system, the electrical continuity of the rail track is also monitored.

This paper presents a methodology for off-line trajectory generation that guarantees high-speed and precise end-effector point-to-point (positioning) control of industrial robot arms, within the bounds of the most relevant constraints. The constraints being addressed are the saturation of joint torque and the limit of Cartesian velocity. In the proposed methodology, shortest path of travel and maximum-joint torque/acceleration utility is guaranteed so that the true minimum-time trajectory is generated. The minimum-time trajectory is then compensated for the delay dynamics using a feedforward compensator. An illustrative implementation is presented using the Performer MK-3s robot arm, with which attractive results have been obtained. Being an off-line algorithm, the proposed method can be conveniently introduced into existing servo control systems of industrial robot arms, and to enhance their performance.

The paper describes the development of a speech trainer based on digital signal processing (DSP) techniques, for hearing impaired children. The DSP techniques investigated in the implementation of this software-based speech trainer, the final" product'and its degree of success in actual use are highlighted. Children with congenital hearing impairments have difficulties in speaking, and even in making the basic sounds associated with speech. Speech therapists use specialized training methods to train such children. The first step in such programs is the training of the pronunciation of common sounds. The dearth of qualified speech therapists, and other facilities hinder the speech development of many children in need of such training.

Contributed papers presented at the Seminar; held as part of the 54th Annual Sessions of Sri Lanka Association for the Advancement of Science.

HKU Scholars Hub: Delay-locked loop techniques in direct sequence spread-spectrum receivers Skip navigation HKU Login Guest Login Home Publications Researchers Staff Research Postgraduates Organizations Grants Datasets Deposit Data HKUL Research Data Management Theses Patents Community Service File Download FullText.pdf Links for fulltext (May Require Subscription) DOI: 10.5353/th_b3124104 Supplementary Appears in Collections: HKU Theses Online Electrical & Electronic Engineering: Theses postgraduate thesis: Delay-locked loop techniques in direct sequence spread-spectrum receivers Show simple item record Show full item record Export item record Title Delay-locked loop techniques in direct sequence spread-spectrum receivers Authors Thayaparan, Subramaniam. Issue Date 1999 Publisher The University of Hong Kong (Pokfulam, Hong Kong) Citation Thayaparan, S.. (1999). Delay-…

Multiple visual features can be used to track objects in environments where the use of a single visual feature is not sufficient. We have proposed an alternative method to feature integration by way of feature substitution where the dominant feature at any instant is used for tracking. The problem of increased computational cost resulting from the use of multiple features is addressed by using software optimization techniques. Here we use software threads and special instructions provided in MMX processors to increase the frame rate. Experimental results indicate that it is not always necessary to adopt a hardware based approach for real time object tracking even when the computational cost is high.

Contour control of a robot arm is an act of the end-eflector being moved along a reference Cartesian path, with an assigned uelocity. While contouring sharp corners and, at the start and the end of the operation, a substantial torque demand is originated from the refer-ence input generator. It causes power amplifier saturation of the servo controller and hence the saturation of joint torque. Once torque saturation occurs, and last for some time, contour deteriorations are resulted. In addition, system delay dynamics also causes contour deteriorations. In this research, optimum avoidance of torque saturation and delay dynamics compensation are achieved by an off-line trajectory generation algorithm and modified taught data algorithm.

The concept of vision information has become a key feature in modern vehicular traffic control and Intelligent Vehicle Highway Systems (IVHS)[1]. Vehicle detection by video cameras is one of the most promising new technologies used in implementing advanced traffic control and management systems [2].

Construction of new highways or expansion of existing highways to meet the everincreasing highway traffic is a very expensive and time-consuming task Management of existing highways effectively is considered as a high priority option in Traffic and Highway Engineering. Trafic control by a system of traffic signal lights and variable message signs that can adapt to the changing environment is an essential part of such management scheme The multiprocessor architecture described in this paper maintains near neighbor connectivity and shares information via these near neighbor interconnections for calculation of optimum traffic plans. The near neighbor connectivity simplifies the expansion of the multiprocessor architecture with city developments

Telecommunications services in Sri Lanka were a total government monopoly until recently. Today, according to international estimates, it is one of the most deregulated telecom markets in Asia with regard to privatization and competition. Recent deregulatory measures, combined with several other social and economic factors have resulted in phenomenal advances in the telecommunications sector. However, the telecommunication revolution has been limited to urban areas, with the rural population being mostly left out. 78% of the telephone lines are concentrated in a few major urban areas, and the main line penetration stood at a mere 1.95% by the end of 1997.

The paper describes the design and implementation of a controller, which rotates an antenna in the optimum direction for reception of signals at the installed loca-tion. The antenna controller can be programmed on-site, with the direction of best reception for each channel. During operation, when a particular channel is selected, the controller will align the antenna in the direction to which it is programmed. This device is ideally suited for TV reception in Sri Lanka, where broadcast stations are placed at a variety of different geographic locations. However, the device is suitable for any application where a requirement exists for antenna re-aligning with geographic location.

HKU Scholars Hub: Gaussian Despreading Chip Waveform for Coherent Code Tracking in DS/CDMA Systems Skip navigation HKU Login Guest Login Home Publications Researchers Staff Research Postgraduates Organizations Grants Datasets Deposit Data HKUL Research Data Management Theses Patents Community Service File Download There are no files associated with this item. Supplementary Appears in Collections: Electrical & Electronic Engineering: Conference papers Conference Paper: Gaussian Despreading Chip Waveform for Coherent Code Tracking in DS/CDMA Systems Show simple item record Show full item record Export item record Title Gaussian Despreading Chip Waveform for Coherent Code Tracking in DS/CDMA Systems Authors Thayaparan, SWang, JNg, TS Issue Date 1999 Citation Proc. International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC'99, …

Development of the hardware, firmware and control and monitoring software to interface the UNIROAD Traffic Signal Controller (TSC) to Advanced Traffic Control system (ATCS) is described. This system is capable of controlling and monitoring traffic signal controllers over a standard telephone link. It is specially developed at a low cost for third world countries such as Sri Lanka.