On a slate-gray Sunday afternoon here in the sickly heart of car-making country, 300 auto workers, their wives and their children gathered recently in a union hall for a terrifying look at the future.

"High technology and robots may eliminate each and every one in this room," proclaimed Ron Murray, president of United Auto Workers Local 735.

The warning could hardly have come at a gloomier time. Layoffs in the past two years have slashed UAW membership in the Ypsilanti local from 11,000 to 6,000. Michigan unemployment stands at 17.2 percent, a post-Depression record. In the union hall, behind the assembled auto workers and their families, hung racks of used clothes -- free for union families short of money.

The keynote speaker for the all-day seminar on high technology and robots was Harley Shaiken -- a union consultant, researcher at the Massachusetts Institute of Technology and nationally prominent dark prophet of automation.

"Today we are looking at an unprecedented situation -- the introduction of a very powerful and pervasive labor-displacing technology against a backdrop of stagnant economic growth," Shaiken said. "So for millions of workers today, the issue is not how many people will be displaced but, for at least 10.8 percent of the work force in the United States, the issue is how many people will never return to the job.

"The danger is, as the economy begins to improve, robots and other automated equipment will return to the job before laid-off workers return to the job."

As Shaiken and other experts explained how robots could turn them into blue-collar anachronisms, the auto workers seemed, at first, bewildered. Then they got mad. By the end of the day, a score or more had stood to denounce the "damn union" for not protecting their interests.

Fear of machines taking jobs from working-class people is hardly new. Since English workers known as Luddites destroyed textile machinery in a failed and bloodily suppressed effort to stop industrialization in the early 19th Century, generation after generation of workers have feared that new machines will ruin their lives. Economists say most of those fears have proved exaggerated.

"We have had the replacement of men by machines for close to 200 years, and it can only be said that unemployment has not grown," says Stanford University economist and Nobel laureate Kenneth Arrow. "I think the answer is that the economy does find other jobs for workers. When wealth is created, people spend their money on something."

While new technology obviously has led to a richer, less brutish world, sometimes the costs--for a region, a race or a class of Americans--have been high. The revolution in U.S. farming technology, which in the past 50 years cut the proportion of Americans working on farms from 21 to 2.6 percent, also helped seed the ghettos of the North. New England, now reviving on the strength of new technology, was impoverished for nearly a quarter century by the postwar exodus of the textile industry. Mechanized coal mining, encouraged by the United Mine Workers in the 1930s, left thousands of Appalachian miners without jobs, skills or prospects.

The symbol of the next great threat to the working man is the robot--a computer-driven machine that for the first time actually looks and moves something like a human being. Robots, along with legions of computerized machines that are beginning to take up their positions in factories, are far more productive than people. They can stay on the job 24 hours a day while maintaining the quality of their work. As computer technology advances, robots rapidly are becoming smarter and cheaper and more attractive to industry.

Since low productivity growth was diagnosed in the late 1970s as one of the nation's major economic problems, pressure has mounted to automate as quickly as possible. Foreign competitors, especially the Japanese, have exacerbated that pressure by taking the lead in turning over blue-collar jobs to computerized machinery.

The rush to automate weighs heaviest on the nation's 18.7 million manufacturing workers, already suffering from 14.8 percent unemployment and concentrated in the depressed Great Lakes region. According to experts in factory automation, for these workers to accept and adapt to robots requires extensive retraining and careful planning by management and labor.

Yet little is being done to prepare and retrain potential victims of the robot era, says Rep. Albert Gore Jr. (D-Tenn.), who this summer was the chairman of congressional hearings on robots.

"For the United States to exploit this technology in a rational way . . . you have to give assurances to people in danger of losing their jobs that they are going to be able to work. We are not doing that today," Gore said, summing up the hearings. He plans to introduce a national robotics bill next year calling for federal spending to support retraining of workers, robot research and a low-cost robot leasing program.

The invasion of industrial robots, which was prematurely predicted for more than a decade, seems finally to have begun in earnest. Robot sales took off in 1979 and are expected to increase through the 1980s at between 35 and 50 percent a year. There are now about 4,500 robots at work in this country, half of them in the automobile industry. By the end of the decade, robots are widely predicted to be a $2 billion industry, and there are expected to be between 150,000 and a quarter million of them at work in U.S. factories. General Motors Corp. alone plans to buy 14,000 robots.

General Electric Co. predicts that the factory automation business, of which robots are only one component, will generate $30 billion in sales by 1990.

Predictions about what robots will do to jobs vary widely. Depending on whom one chooses to believe, one robot can replace six workers, 2.7 workers, 1.7 workers or no workers.

If there are 15,000 robots in use in three years, 90,000 people will be displaced, says Paul Aron, a robot expert with Daiwi Securities America. Thomas G. Gunn, of the Arthur D. Little consulting firm, says the factory work force will be cut by between 20 and 25 percent and up to 4 million jobs could disappear by 1990. And a Carnegie-Mellon University study last year said that the first generation of robots (which are blind and very stupid) could replace about 1.2 million workers. A second generation of seeing and feeling robots, which are just starting to be sold, could replace 3.8 million jobs, the study said.

Whatever the job-evaporation numbers turn out to be, the most immediate robot threat is to unionized metal workers and to the Great Lakes States where they are concentrated. Robots have been--and in the near future will be--used most successfully in welding, moving metal around and loading machine tools, all of which are highly unionized tasks. According to the Carnegie-Mellon robot study, unions also are vulnerable because "the occupations with higher wage rates will most likely be the first candidates for replacement."

All this makes auto and metal-working unions apprehensive:

"It is damn hard, in the middle of this recession, with the machine tool industry operating at 52 percent capacity, to estimate the effect of this on the machinists union," says Dick Greenwood, an executive with the International Association of Machinists and Aerospace Workers. "But what we have is the distinct prospect of building this super-high-tech economy over a hollow salt dome of double-digit unemployment. We could create a large class of permanently unemployed people. For a society that is so committed to the work ethic, this could fracture a lot of minds."

In the past two years, several major union contracts covering auto, communications, electrical and machine workers have been negotiated to include advance notice of new technology and retraining for displaced workers. The United Auto Workers traded wage increases for job security in recent contracts. A UAW contract with Ford this year established a national training program for laid-off workers and for those whose skills rapidly are becoming antiquated.

The machinists union recently has put together a Technology Bill of Rights, which demands the right to help management decide what new technology to buy, requires employers to pay a "robot tax," and orders management to share with workers the wealth create by automated factories. Communications workers, represented by the Bell System Bargaining Council, plan next year to consider asking that half the productivity gains of new technology be devoted to retraining.

Thus far, none of these demands has been written into major union contracts, and several union leaders say the demands represent wishful thinking.

Robots, of course, also will create jobs. The Bureau of Labor Statistics predicts that about 800,000 jobs will be created in industrial robot production by 1990; it also says that one of the fastest growing job markets will be for high-tech engineers.

James S. Albus, a robot expert at the National Bureau of Standards, claims that Harley Shaiken and others who issue apocalyptic warnings about widespread technological unemployment are short-sighted.

"The basic fallacy with Harley's argument is that he is looking at a specific isolated industry and not at the overall picture," says Albus, author of two books on robotics and acting chief of a federal laboratory that is developing programmable robots. Albus says that the robot industry, doubling in size every three years, will create more jobs than it eliminates.

"A typical industrial robot costs between $30,000 and $100,000, and sometimes more, by the time it is installed and operating. This means that every robot installed creates from two to four person-years of work somewhere in the economy," he asserts. "Robot production will add jobs to the economy at least as fast as robot installation takes them away. And the increase in wealth produced will more than cover the job relocation costs.

"To say that we can't proceed in robotics until we have this grandiose plan to save jobs means that we cannot proceed. That kind of planning has never been done and never will. To some extent, life is an adventure."

Many robot experts claim that the United States, which is far behind the Japanese in robot production, does not have time to debate whether robots and automated factories will have positive sociological effects.

"Sure, if the new technology of the automated factory is adopted as quickly as possible, it will force great changes in education, work patterns and in industry," says Philippe Villers, a high-tech entrepreneur, proselyter of robotics and founder of Automatix, a Boston robot company.

"But if the automated factory is not adopted as quickly as possible, it will mean even greater changes for this country. It will mean the loss of competitive advantage for industry, a lower standard of living for everyone, high unemployment and a general feeling of dissatisfaction as we go from being a world leader to being a world follower," Villers says.

The Japanese, utilizing tax breaks, government research subsidies and a low-cost loan program, already have put about 14,000 programmable robots to work, nearly three times the American number. In 1985, there are expected to be 85,000 to 100,000 robots in Japan.

The Japanese also have about 60 unmanned or semiautomatic factories operated by so-called "flexible manufacturing systems," which consist of computer-linked machine tools, automatic conveyors, robots and automatic inspection equipment. There are only "a little more than a handful" of these automated factories in the United States, according to Charles E. Lamb, General Electric's manager of manufacturing automation systems.

Although they are very expensive to build, automated factories can make things for less cost than manned factories. Robots in the United States, for example, cost about $6 an hour to buy and maintain compared with an average labor cost of $15 an hour. Industry experts say that most robots pay for themselves in less than three years.

The Japanese push to automate--an effort initiated and planned in many respects by the Japanese government--has the potential to threaten not only highly paid American industrial workers, but to displace even low-paid workers around the world.

"Japan's onslaught to proliferate robotic systems will have a serious impact on developing countries, which up to now were able to supply labor-intensive parts, components and finished products to the markets in the advanced countries because of their labor cost advantage," Joji Arai, manager of the U.S. Liaison Office with the Japan Productivity Center, told a congressional subcommittee this summer.

Arai warned, however, that automated manufacturing "will undoubtedly widen a gap between the advanced and developing countries, forcing a confrontation with the Third World."

Japanese workers, meanwhile, are far more accepting of robots than U.S. workers. In a report to Congress on robot use in Japan, robot expert Paul Aron says factory workers there don't object to robots because many of the workers are guaranteed lifetime employment, have a voice in deciding how to use robots and receive bonuses based on productivity increases.

"So for the Japanese employe, the battle cry is 'Bring on the robots,' because for many it means greater pay, greater bonuses and a greater chance to move up the ladder," Aron says.

Many automation experts argue that, for robots to be widely accepted in the United States, workers must be persuaded that the machines will benefit them. Says Thomas Gunn, automation expert for Authur D. Little: "There is no way that we can implement these systems without labor cooperating."

So far, however, some union leaders have complained that the new technology not only threatens job security, but "de-skills" workers by turning them into button-pushers and wrests control of production away from workers, giving it to managers.Although there has been little public protest against robots, robot companies say worker acceptance of the machines is often less than warm.

"Just about every company has had some problem with acceptance of the robots--misgivings from the rank and file," says Ken Ellis, a training specialist for Cincinnati--Milacron, the second-largest U.S. robot maker. "You go to any company and, if they are honest, they will say that acceptance hasn't been complete."

In a speech last year at Harvard, Glenn E. Watts, president of the 650,000-member Communication Workers of America, said labor is "fighting against a growing trend toward centralization of management control and re-education of shop-floor jobs into . . . mindless tasks with no sense of service or accomplishment."

The first jobs taken by robots in this country, such as assembly-line spot welding, were hot, heavy, hazardous and boring. But the new generation of "smart" robots will be capable of taking away more attractive--if still repetitive--light assembly jobs.

A Carnegie-Mellon survey found last year that the overwhelming reason why business buys robots is to reduce labor costs--not to improve working conditions. Accordingly, some industry experts fear that robots may not fulfill their potential to eliminate miserable jobs.

The fear is heightened by secrecy about robot installations. Cincinnati-Milacron says 20 percent of the robots it sells outside of the auto industry are under "secrecy agreements" that prevent the company from talking about how the robot is used. The Carnegie--Mellon study found "almost all" firms that have done extensive research on robots "consider this information to be confidential and are reluctant to discuss their results."

"There is a real danger as the technology leaps ahead that robots will not take the noxious jobs, but will be applied to more skilled tasks which offer higher returns to business," says Neale W. Clapp, an industrial psychologist who, as a consultant for General Electric, surveyed how labor and management react to robots.

"I fear some of the more noxious jobs will be untouched by robots," says Clapp. "If businesses only look at robots for economic reasons, they are going to put their money where it makes good economic sense, not necessarily humane sense."

The capacity of robots and automated factories to make high-quality products and generate enormous wealth is taken for granted by most people in robotics.

" According to Dick Greenwood of the Machinists union, the question is, "How do you distribute that wealth? Who is going to share it?"

At the congressional hearings on robots this summer, Albus, the robot researcher from the National Bureau of Standards, suggested that the United States could automate more rapidly if there were "a social compact that guarantees that the wealth generated by these new machines . . . would be adequately and equitably distributed so as not to result in massive unemployment and dislocation."

The chairman of the hearings, Rep. Gore, responded: "Good luck."