| Programming of mechanical manipulators or robots is currently either by guiding or by specifying arm motion symbolically in a programming language. Guiding is suitable when the arm goes through the same sequence of operations repeatedly; it is unsuitable for making decisions, programming actions based on real-time sensory data, or concurrent action. Programming languages overcome some of these limitations; however, they require detailed instructions for performing even the simplest tasks in assembling parts, and the user requires special training to program the arm. Manipulators will be used extensively for industrial assembly in the future. Therefore, some means to simplify manipulator programming is needed.; Experience in using manipulators was gained by programming the assembly of flashlights, lawn sprinklers and other objects using AL, an interactive programming language for robots at the Stanford Artificial Intelligence Laboratory. Analysis of the programs disclosed commonly repeated sequences of operations.; Examination of Industrial Engineering techniques revealed that the Methods Time Measurement (MTM) system was an extensive body of knowledge for analyzing human motions while performing various tasks. Many sequences of operations in programming mechanical arms were found in MTM.; Motion Sequencing of Manipulators (MSM) for describing and specifying operations for mechanical arms was proposed after analyzing mechanical assembly programs and studying MTM. There are several levels of MSM elements or primitives: MSM-1 (arm primitives) include REACH, MOVE, GRASP and OPEN HAND for the mechanical arm and correspond to REACH, MOVE, GRASP and RELEASE in MTM-1 for humans; MSM-2 (assembly primitives) include those for interactive teaching, state-checking or inspection, action (such as GET, PUT, RELEASE of objects), and synchronization; MSM-3 (task primitives) include those for locating parts, setting up parts, and actions to handle insertion, palletizing, de-palletizing, and obtaining parts from feeders.; The MSM procedure was implemented in AL and evaluated by various people familiar with Industrial Engineering and manipulator programming languages. They concluded that MSM is more succinct, simpler and has fewer commands than AL. Programming in higher levels of MSM is easier than in AL. Since it uses the vocabulary of MTM, MSM is a viable means for programming assemblies for engineers who are familiar with MTM. |
