In a General Motors Corp. assembly plant in the Cincinnati suburb of Norwood, industrial robots are doing what was once the work of men.

The same is true at the other end of Ohio near Youngstown in GM's large Lordstown assembly plant. At both plants robots serve as welders.

But industrial robots can perform more complex functions, too. For example, they can load punch presses, move heavy parts, mount wheels, and load and unload machine tools.

Technological advances indicate greater use for industrial robots in the future; eventually they will do much assembly work, Dr. Charles Rosen of SRI International told a United Auto Workers union delegation at a recent conference on technology. His California-based firm does research into the use of robots.

Auto workers are reacting to the increased use of industrial robots as they have to other advances in automation: They are welcoming the trend so long as they share in the benefits of advancing technology.

Not only are many of the 900,000 to one million workers represented by the union assured of pay adjustments reflecting increased productivity because of their contracts with the major domestic auto producers and many smaller companies, but the UAW insists that workers whose jobs are abolished by automation fill the positions created by the automation. An example would be giving a welder displaced by a machine the job of maintaining and programming that machine.

And automation does create new jobs. One overseer is needed for every five robot units, according to Joe Engleberger, president of Unimation, a leading producer of robot units based in Connecticut.

Rosen of SRI Internationaal told the technology conference that producing new automated tools will create a very large new industry to make these tools and to install, service and modify them.

In fact, this new industry probably will create more jobs than were abolished by the use of automated machines for many years, he said.

To date, however, the effect of industrial robots on the nation's labor force has been less than massive. Unimation, for example, is shipping only about 40 units a month.

Among factors dictating the slow pace are a shortage of investment capital-the more expensive undustrial robots can cost more than $100,000-a need for more workers to program and maintain them and, perhaps most importantly, the conservatism of the manufacturers who must decide whether to buy them, Engleberger said.

Nonetheless, he cited the rising cost of human labor as perhaps the chief reason to use industrial robots. In the auto industry, the cost of human labor-including fringe benefits-has more than tripled from $3.80 an hour in 1960 to $14 today, while the cost of the robot units-higher than for humans in 1960 at $4.20 an hour-has risen only to $4.80 today, Engleberger said.