The industrial robot cut it's teeth in the automotive industry. The production volumes and shift patterns enabled many applications to be automated with ease. 2/3 shift patterns ensured very attractive payback periods and returns on investment.

Production processes enabled the industrial robot to be applied using three discrete approaches. A typical manual automotive assembly line is a continuously moving conveyor track and floor, to enable workers to remain static relative to the vehicle being built whilst travelling through the assembly plant.

Robot modes of automation as follows:

Conveyor tracking - robot follows moving vehicle build

Transfer Line - indexing with static work positions

Cell - Islands of automation offline

Typical examles of the three modes of automation are as follows:

Conveyor Tracking (continuous moving track)
This method is the earliest and least successful of the three. Simplistic thinking looked to replace the operative in situ, that is to say put in a robot to do the same task. The human operative would constantly monitor the vehicle position and modify his position to accomodate the change. The robot could only work with known locations so a variety of strategies were developed to overcome the robot's shortcomings.

The first solution put the robot on a linear track adjacent to the assembly line. When the track received a signal it would traverse at the same speed as the line negating any relative movement between the two.

As computer control developed and constant velocity and tip speed control were made available, the robot could follow the track, 'in program', although this had serious implications for the work envelope.

Whilst both were theoretically possible the practicalities made applications difficult or impossible. Existing assembly lines were not built for automation and their performance varied dependent on loadings and ouptut speed. 'Stickage' was a real problem which prevented smooth operation resulting in relative position changes, at high speed. Difficulties encoding conveyor position also resulted from tensioning inconsistencies.

Applications included; Spot Welding, Windscreen Assembly, Paint Inspection and Wheel Assembly.

Transfer Line (Indexing)