Path and orientation accuracy of industrial robots

The automotive industry uses mainly on-line programming, i.e. teach-in programming, of welding and bonding robots for path planning purposes. This programming method is very time-consuming and expensive, and short-term program modifications cannot be easily performed. Computer-aided simulation of the working program and subsequent off-line programming seems to be one possible solution. Unfortunately, off-line versus on-line programmed paths entail completely different robot performances. As robot manufacturers are unable to provide data on the off-line path accuracy of their products, this type of programming is not suited for practical operation. This problem will be discussed on the basis of directive VDI 2861, and for the first time results of off-line and on-line path measurements will be compared.