- Email: [email protected]
The basic fault-tolerant system
Miihlbacher, l R and Steinparz, F X 'Transformation of co-ordinates for robot control'J. Microcomput. Appl.
inary use of the system and ways of improving the algorithm in future work.
Vo17 No1 (1984) pp1-17 A mathematical description is given of coordinate transformations needed to describe the motion of a robot's effector through points in three-dimensional space. It is assumed that the effector of the robot is just a point. The transformations are carried out in practice using an algorithm based on Davenit-Hartenburg matrices. However, this algorithm can hide the geometric properties of the robot. Hence the authors use concepts of elementary geometry to show the transformation steps as applied to robot control. Several coordinate transformations using two and three axes are explained. The theory is illustrated by a case study of the laboratory robot used by the authors.
Naghdy, F, Stoodley, K D C, Henry, R M and Crew, A D 'Development of a microprocessorbased monitoring system for postsurgical cardiac patients' ]. Microcomput. Appl. Vol 7 No 1 (1984) pp 41-49 A univariate index of cardiovascular status has been constructed. The index is for use in monitoring patients in a post-surgical cardiac intensive-care unit. It is constructed on the basis of the patient's skin temperature and mean blood pressure, since these have been shown to be the most sensitive indicators of long-term changes in the patient's cardiovascular status. FORTRANalgorithms smooth and forecast a time series formed from values of the index calculated at regular intervals. The algorithms were implemented on a Z80, while housekeeping routines were written in assembly code. Construction of the monitoring algorithm is described. An account is given of the software architectu re and its development, followed by online implementation of the system. The authors indicate difficulties encountered in the prelim-
388
Ross, S and MacAIlister, J 'Practical and continuous speech recognition' Comput. Des. Vol 23 No 7 (15 June 1984) pp 69-76 Continuous-speech recognition is difficult because a word's pronunciation varies depending on its context in a sentence. Moreover, word boundaries are poorly defined in continuous-speech signals. A system to overcome these problems has been built around an 8086 control processor. The model 3000 contains two to four speech processors and an audio processor. Ross and MacAIlister list the hardware selected for the system. They give a step-by-step account of how the system works. Two algorithms developed to verify the design of the algorithm software are described. An example of a typical grammar for speech recognition is given. Practical advantages of continuous speech are summarized.
Schmitter, E J and Baues, P 'The basic fault-tolerant system' IEEE Micro Vol 4 No 1 (February 1984) pp 66-74 Developers of fault-tolerant microelectronics systems face several problems: fault diagnosis, data integrity and task distribution, reconfiguration and recovery. Schmitter and Baues propose a basic faulttolerant system (BFS) to meet various requirements. Fault tolerance should be confined to hardware faults. Redundancy inherent in a multimicrocomputer system must be used to minimize the need for extra redundancy. Only commercially available, standard components can be used. The network architecture should be as simple as possible and result in a functionally clear software structure. Schmitter and Baues discuss the hardware and software structures of BFS. They suggest areas in which it might be most useful. Fault tole-
rance in distributed systems was the first application of BFS. This implementation is described. Local area networks can also use BFS, say the authors. They indicate how, and include a summary of basic topologies for local area networks. While BFS was deemed to give reasonably good results in practice, the authors conclude that it is still too software oriented and needs more hardware support.
Sibiglroth, J M 'Motorola's MC68HC11 : definition and design of a VLSI microprocessor' IEEE Micro Vol 4 No 1 (February 1984) pp 54-65 Attention in the computer industry may be centring on designs in 16and 32-bit microprocessors, but 8bit VLSI is still progressing with 'giant steps', says Sibigtroth. He predicts an increasing use of 8-bit microprocessors in applications that need control functions. One development is Motorola's MC68HCl 1, made using HCMOS methods. This 8-bit chip has more circuitry than the 16-bit 68000. It has an onchip E2pROM and a successive-approximation A/D converter. Sibigtroth goes through the design process for the MC68HC11, stage by stage, from the selection of the CPU architecture to the generation of optical mask plates for making the parts. Block diagrams of the main timer and the serial communication interface are given. Specific decisions that had to be made in the course of design are highlighted, eg whether to include a Stop instruction in the MC68HC11. Each of the main components on the chip is treated separately in a short subsection.
Singh, L and Ahson, S I 'Microprocessor monitoring of an HVDC thyristor converter'J. Microcomput. Appl. Vol 7 No I (1984) pp 51-61 A monitoring system for a highvoltage DC (HVDC) thyristor converter has been developed. The
microprocessors and microsystems
inary use of the system and ways of improving the algorithm in future work.
Vo17 No1 (1984) pp1-17 A mathematical description is given of coordinate transformations needed to describe the motion of a robot's effector through points in three-dimensional space. It is assumed that the effector of the robot is just a point. The transformations are carried out in practice using an algorithm based on Davenit-Hartenburg matrices. However, this algorithm can hide the geometric properties of the robot. Hence the authors use concepts of elementary geometry to show the transformation steps as applied to robot control. Several coordinate transformations using two and three axes are explained. The theory is illustrated by a case study of the laboratory robot used by the authors.
Naghdy, F, Stoodley, K D C, Henry, R M and Crew, A D 'Development of a microprocessorbased monitoring system for postsurgical cardiac patients' ]. Microcomput. Appl. Vol 7 No 1 (1984) pp 41-49 A univariate index of cardiovascular status has been constructed. The index is for use in monitoring patients in a post-surgical cardiac intensive-care unit. It is constructed on the basis of the patient's skin temperature and mean blood pressure, since these have been shown to be the most sensitive indicators of long-term changes in the patient's cardiovascular status. FORTRANalgorithms smooth and forecast a time series formed from values of the index calculated at regular intervals. The algorithms were implemented on a Z80, while housekeeping routines were written in assembly code. Construction of the monitoring algorithm is described. An account is given of the software architectu re and its development, followed by online implementation of the system. The authors indicate difficulties encountered in the prelim-
388
Ross, S and MacAIlister, J 'Practical and continuous speech recognition' Comput. Des. Vol 23 No 7 (15 June 1984) pp 69-76 Continuous-speech recognition is difficult because a word's pronunciation varies depending on its context in a sentence. Moreover, word boundaries are poorly defined in continuous-speech signals. A system to overcome these problems has been built around an 8086 control processor. The model 3000 contains two to four speech processors and an audio processor. Ross and MacAIlister list the hardware selected for the system. They give a step-by-step account of how the system works. Two algorithms developed to verify the design of the algorithm software are described. An example of a typical grammar for speech recognition is given. Practical advantages of continuous speech are summarized.
Schmitter, E J and Baues, P 'The basic fault-tolerant system' IEEE Micro Vol 4 No 1 (February 1984) pp 66-74 Developers of fault-tolerant microelectronics systems face several problems: fault diagnosis, data integrity and task distribution, reconfiguration and recovery. Schmitter and Baues propose a basic faulttolerant system (BFS) to meet various requirements. Fault tolerance should be confined to hardware faults. Redundancy inherent in a multimicrocomputer system must be used to minimize the need for extra redundancy. Only commercially available, standard components can be used. The network architecture should be as simple as possible and result in a functionally clear software structure. Schmitter and Baues discuss the hardware and software structures of BFS. They suggest areas in which it might be most useful. Fault tole-
rance in distributed systems was the first application of BFS. This implementation is described. Local area networks can also use BFS, say the authors. They indicate how, and include a summary of basic topologies for local area networks. While BFS was deemed to give reasonably good results in practice, the authors conclude that it is still too software oriented and needs more hardware support.
Sibiglroth, J M 'Motorola's MC68HC11 : definition and design of a VLSI microprocessor' IEEE Micro Vol 4 No 1 (February 1984) pp 54-65 Attention in the computer industry may be centring on designs in 16and 32-bit microprocessors, but 8bit VLSI is still progressing with 'giant steps', says Sibigtroth. He predicts an increasing use of 8-bit microprocessors in applications that need control functions. One development is Motorola's MC68HCl 1, made using HCMOS methods. This 8-bit chip has more circuitry than the 16-bit 68000. It has an onchip E2pROM and a successive-approximation A/D converter. Sibigtroth goes through the design process for the MC68HC11, stage by stage, from the selection of the CPU architecture to the generation of optical mask plates for making the parts. Block diagrams of the main timer and the serial communication interface are given. Specific decisions that had to be made in the course of design are highlighted, eg whether to include a Stop instruction in the MC68HC11. Each of the main components on the chip is treated separately in a short subsection.
Singh, L and Ahson, S I 'Microprocessor monitoring of an HVDC thyristor converter'J. Microcomput. Appl. Vol 7 No I (1984) pp 51-61 A monitoring system for a highvoltage DC (HVDC) thyristor converter has been developed. The
microprocessors and microsystems