NSRDS Bibliographic Series – serie

In contrast to the effortless ease with which human beings control their limbs, the design of controllers for robotic manipulator arms is a detailed, meticulous business. Motors controlling the arms need to be started and stopped at just the right moment so that the performance demanded by the user may be achieved at the end of a complicated manoeuvre. And yet, the same user wishes to express the task for the robot in the simplest possible terms without reference to the minute details of control sequences that his task demands. It is the design of such inter­ faces between man and machine that is the subject of trus volume. Parent and Laurgeau develop the subject in a direct and logical order. They first explain the principles of maximal effort control which not only ensure that motors are driven to provide high accuracy, but also that this should be done with the least waste of energy and in the shortest possible time. In this context, they describe the operation of pneumatic logical devices that make rapid decisions at power levels that exceed, by several orders, those that can be achieved with electronic devices. They achieve this whilst keeping the reader aware of the logical principles that are involved in the design of master control units: the devices responsible for appropriate actions being taken as a function of time.

Coverage For some time, we have contemplated a comprehensive review of the structures and force fields of the binary fluorides. This bibliography of 1498 references marks the first step of that effort. We are pub­ lishing this material now rather than waiting until the review is complete some two years hence because we believe that the information already accumulated will be of immediate use to a broad spectrum of researchers. Anyone ambitious enough to read through all the articles on binary fluorides will find that the struc­ tures and force fields of many of these molecules are at present unknown. For example, it has not been clearly established to which point group(s) the lanthanide trifluorides should be assigned. There remain interesting problems relating to the role of Jahn-Teller and pseudo-Jahn-Teller distortions in some of the transition metal fluorides such as VF , MoF , ReF , and ReF , to name only a few. One s s 6 7 also finds fascinating examples of large-amplitude motions, or pseudorotations, as they are often called, in such molecules as XeF 6, I F 7, and PF 5' For those binary fluorides whose equilibrium geometries are precisely known, there still exists the problem of accurately determining the harmonic force field. In a few cases, most notably the Group VA trifluorides, there has been some attempt made at extracting the cubic and quartic contributions to the force field.

What are the design or selection criteria for robots that will be capable of carrying out particular functions? How can robots and machines be installed in work locations to obtain maximum effectiveness? How can their programming be made easier? How can a work location be arranged so as to accommodate successfully automatic machines? Traditionally, these questions have only been answered as a result of long and exhaustive study, involving complex calculations and the use of many sketches and plans. Computers and interactive computer graphics provide the possibility of automation for this type of analysis, thus making the task of robot designers and users easier. This volume is concerned with mathematical modelling and graphics representation of robot performance (eg their fields of action, their performance index) as a function of their structure, mechanical parts and memory systems. Used in conjunction with operating specifications, such as movement programs and computer-aided design (CAD) data bases that describe parts or tools, these perform­ ance models can allow the potential of different robots or different models of the same type of robot to be compared, workstations to be organized efficiently, responses to be optimized, errors to be minimized and can make off-line programming by computer a real possibility. In the future, it is certain that the appearance of robots designed to monitor their own performances will allow applications and safety conditions to be considerably improved.