The visitor driving up to the yellow Fanuc Ltd. factory here in the foothills of Mount Fuji instinctively feels that something is missing: there is no parking lot immediately visible for the thousands of cars normally found at a place like this.

And then it dawns: the robots working inside don't need cars to drive to work.

Fanuc's Fuji complex, which specializes in the production of computer-controlled machine tools and robots, was begun in 1980 and completed late last year. Operating around the clock, it now accounts for about half of the world's robot production, and in Japan's highly competitive and mushrooming robotics industry, the motor manufacturing division is considered the world's most advanced computer-controlled "unmanned" factory.

At the Fuji complex, there are 60 humans working with 101 robots in the motor factory, and about 100 employes in the Mechatronics Manufacturing Division that produces robots and computerized machine tools that can be programmed to change their machining operations. Along with robots, these machines, commonly called "NCs" (for numerically controlled), have revolutionized manufacturing.

The number of human employes in this production complex is estimated to be only about one-sixth of those needed for a conventional Japanese plant of comparable size. The monthly production capacity includes 40 different kinds of control motors totaling 10,000 units, 300 robots, 100 wire-cutting machines and 100 NCs.

What makes the Fanuc plant so special is that the whole process comes within a hair of the science-fiction fantasy of "robots making robots." Here at the Fuji complex, Fanuc boasts a unique "flexible manufacturing system," integrating the computer-operated machine tools, assembly robots, automatic delivery carriers, and an automated warehouse with central computer control of the whole factory.

It is very close to eliminating human beings entirely from the production process. Many of the humans who remain are managerial, clerical, or inspectors, rather than actual production workers. In this arena of advanced automatic operations, Japan is widening its lead over its rivals in the United States and Europe in the commercialization of robots, even though they retain the technological lead in "intelligent" robots.

Inside the complex, the eerie silence confirms the reality: as you look out at the antiseptically clean, enormous shop floor--20,000-square meters--you must search hard for a human being. Yellow-painted Fanuc robots are relentlessly, methodically, and reliably at work. So are the computer-controlled machine tools. Unmanned yellow transport carts swerve around the robotized assembly lines, picking up or disgorging parts, sounding a warning siren reminiscent of a European ambulance or police car.

But closer inspection does turn up some human workers here and there, clad in yellow work suits and yellow baseball caps.

Why the yellow motif? Takeshi Kawamoto, manager of the technical training center, said there was no special reason, but smiled: "Perhaps it is a restful color, good for concentrating."

All told, there are three buildings at Fanuc's Fuji complex--the motor factory, the Mechatronics division, and a technical training center. (Mechatronic refers to a combination of mechanical and electronic technologies.)

The training center, opened in April 1982, is a typical Japanese touch. There, engineers for Fanuc customers spend up to a month learning how the machine tools or robots operate--and custom-adjust them to their own companies' production requirements on the shop floor. (Fanuc provides dormitory, recreation, and eating facilities accommodating up to 100 people.)

Essentially, the machining process is totally unmanned. Through the night, the machining centers operate automatically, finishing a predetermined amount of work by morning. Just one man sits at a video monitoring display, observing the robots at work, and running the entire facility. A red light, which officials said is "rare," indicates a problem or malfunction at any robot station. The unmanned machining operation can continue for a full 24-hour cycle if necessary.

The huge machine-shop area, run by the robots and NCs, must be seen to be fully appreciated. Instead of a lathe that turns a piece of metal just one way, or a drill that repetitiously drills a hole in the same place, the "NCs," each with a micro-processor in command, control the speed and movement of several different machining operations. Before the advent of the NC--Fanuc built Japan's first in 1956--a design change in the metal being cut or shaped would require suspension of operations until the tool could be altered. Now, the NC is simply reprogrammed.

Robots and numerically controlled machine tools produce motors and other robot parts on one floor. These parts are then automatically delivered by what the Fanuc people call "the unmannned carrier" to a warehouse and ultimately to a second floor, where they are assembled automatically into final products (as designed by Fanuc's customers).

The assembly operation is performed by one or more robots working as a "team" (which Fanuc calls a cell): the unmanned carrier delivers the necessary parts from the warehouse onto a kind of work-bench or "pallet" in front of the robot. Roughly one human worker is assigned to monitor the progress in five complete "cells."

When the cell finishes with its particular assignment, the robot--which has been counting the parts and the finished work--sends for the unmanned carrier. It comes "beeping" along, picks the work off the pallet, and brings it to the next cell. Eventually, the finished part or product is delivered to the automatic warehouse.

The robots most familiar to the American public are the "playback," or sequence, machine such as a welding robot on an auto assembly line that performs a task over and over again. Spray-painting is another such "playback" function. Even though the playback robot has revolutionized auto production, it basically is a first-generation machine.

At Fanuc, in addition to playback robots, there are the more sophisticated assembly robots, incorporating a computer, which belong to a second generation--although not yet so advanced as to have "thinking" power. But the assembly robots are able to move in several directions, and perform multiple tasks in sequence.

It is amazing to watch a single assembly robot efficiently pick up a die-cast housing (still unmachined), put it in a furnace where a flexible channel is cut into the housing, take it out of the furnace, then pick up a steel cylinder and place it in the housing. The robot then carefully stacks the housing on the pallet. Eventually, it is carried off to the next operation by the unmanned carrier.

Asked if the robot ever drops the housing, the complex manager, Hiromichi Shichida, replied, "Once in a while."

In another operation, where a robot has to thread a wire through a hole with a narrow tolerance, it is watched by a video sensor that automatically adjusts the robot if it isn't making the right connection.

Ironically, the only part of the Fanuc operation that is not fully automatic is the final assembly of the robots--which now are of three types: machining, assembly, or special-purpose. Human hands are still necessary to fit the robot pieces together in a standard sort of assembly line procedure, which Shichida said now is yielding about 100 robots a month. (Fanuc's annual report claims a 300-a-month capacity. But current business is below par, officials said, requiring discounts. Signs reading "Costs 30 Percent Down" are spotted around the plant, presumably to encourage economies).

Fanuc changed its corporate name from Fujitsu Fanuc Ltd. last year. It is partially owned by Siemens AG of West Germany. Operating revenue for fiscal 1981 was 92.3 billion yen, or $388 million, against which it showed income of 32.1 billion yen, or $135 million, an eye-opening percentage.

The Fanuc company has a well-established sales organization in Europe and South Africa, and soon will be producing robots in joint operations in the Detroit suburb of Troy, and in England and South Korea. Fanuc and General Motors will start construction this year of a 60,000-square-foot robot factory, employing 50 human workers, that is scheduled to be operational by 1985. The Fanuc British operation, personally encouraged by Prime Minister Margaret Thatcher, will be in Colchester in southeast England--and known as 600-Fanuc Robotics Ltd. The Korean operation will be with the Kolon Group there.

So far, robotization in Japan has eliminated many rough, dirty, or dangerous jobs, and because of actual shortages of skilled labor, there has been little union opposition. Commentator Yoshikazu Kano wrote in the Japanese Economic Journal (Nihon Kezai Shimbun):

"Today robots and (Japanese) workers are enjoying a honeymoon. Young employes hope they will be assigned to the company's robot section. They think of robots as their subordinates. . . . Working with robots makes them feel as though they have been promoted to a supervisory position. Some of them even regard their robots as friends or lovers and give them affectionate nicknames."

There are an estimated 20,000 high-quality industrial robots in operation, world-wide, of which an estimated 70 percent are in Japan. But, Kano asks, what happens when the rate of annual robotic production hits 100,000, including many intelligent robots that take over jobs still reserved for humans? What happens when robotization spreads to the smaller Japanese manufacturing shops, where lifetime employment has never been guaranteed?

These and related socially provocative questions are for the first time being raised seriously in Japanese business, union, and academic circles. But in an interview in his Tokyo office, Fanuc President Sieuemon Inaba, 58, indicated he feels that the danger point for Japanese society is still far off.

Inaba points out that Japan lags behind both the United States and Europe in basic research in the field of high-efficiency robots, including the next generation of intelligent robots with visual function and the ability to "walk around the factories and offices on their own feet," and those connected with CAD/CAM (computer-aided design and computer-aided manufacturing) systems.

Inaba denied that Fanuc or any other robotics maker in Japan had encountered organized union resistance. He insisted that as more robots are introduced, it will "improve the quality of the job." He has also been quoted as saying that the only way by which Japan's factory productivity can be improved in the future is by striving for complete automation.

At his Fuji complex, Inaba is seemingly well en route to his goal. On a factory-automation scale of 0 to 100, Fanuc rates its Motor Manufacturing Division at around 80. The manual assembly of the last stage of the robots in the Mechatronics division and some hand-wiring of some types of motors drags the average down for the complex as a whole. But by the end of the decade, Fanuc's target for its robot-assembly division is 50 percent, which would bring the automated average of the whole Fuji complex up to 65 percent.

At this level, worker resistance to robots could stiffen. Last month, the Nissan Motor Co.--a big robot user--for the first time promised to consult its 47,000-member company union on any further automation, and promised that new robots won't lead to a loss of jobs among the present work force.

But the future is unclear, especially for new entrants to the labor force. A publication on robots edited by Kinji Kawamura of the Foreign Press Center of Japan points out that even if robot-displaced workers can be transferred to other jobs, the adjustment process may be difficult or unsatisfactory. In the long run, Kawamura said, labor unions fear that employment opportunities will be limited.

And a Japanese woman seeing the Fuji complex for the first time articulated the problem for the remaining human workers. "Who," she wondered out loud, "can those few men in there talk to? The robots?"