← Back to Library

High-five to the Belgrade hand

Asianometry uncovers a forgotten chapter of robotics history that challenges the modern obsession with computational power, revealing how a Yugoslav scientist in the 1960s solved the problem of dexterity not with faster chips, but by mimicking the messy, error-maximizing logic of biology. While today's AI-driven robots often stumble over simple grasping tasks due to rigid programming, the author argues that Rako Tomovich's "Belgrade Hand" succeeded by embracing a radical, counter-intuitive control theory that prioritized sensory feedback over precise mathematical models.

The Biology of Error

The piece begins by dismantling the assumption that robotic precision requires rigid control. Asianometry notes that while the human hand relies on 35 actuators, the real magic lies in how it processes feedback. "In a 1965 interview with a US newspaper, Tomovich said, 'We are not concerned with changing the hardware. Rather, we're working on introduction of new mathematics techniques in computer use.'" This pivot from hardware to theory is the article's intellectual anchor. The author explains that traditional control systems of the era sought "zero error," constantly trying to match a sensor reading to a pre-programmed target. Tomovich argued this was fundamentally flawed for real-world interaction.

"Zero error might be helpful for certain cases like industrial robot arms but is not suitable in life where you encounter new and different things all the time."

This insight is profound because it anticipates the current struggle in robotics: the inability of top-down systems to handle unstructured environments. Asianometry highlights Tomovich's alternative: a system that "maximized error." Instead of minimizing the gap between where a hand is and where it should be, the Belgrade Hand was designed to maximize the feedback signal from skin contact until the grip was secure. The author writes, "Instead of telling the hand exactly where to go to clasp something, give it a few loose goals and conditions and let it figure it out on its own via an error maximization feedback loop." This reframes the robot not as a calculator, but as an adaptive organism. Critics might note that this approach relies heavily on the specific mechanical design of the glove and springs, potentially making it less transferable to modern digital sensors without significant re-engineering.

High-five to the Belgrade hand

A Mechanical Marvel in the Cold War

The narrative then shifts to the historical context, painting a vivid picture of Tomovich's journey from a World War II veteran and nuclear researcher to a prosthetics pioneer. The author details how the first Belgrade Hand, presented in 1964, was a five-fingered marvel that operated without a large digital computer. "Unlike another pioneering robotic hand, the MH1 produced at MIT by Hinrich Ernst in 1962, the Belgrade hand's intelligent capabilities were achieved without the use of a large digital computer attached to it." This distinction is crucial; it suggests that intelligence in robotics is not solely a function of processing power but of control architecture.

The article describes the hand's unique grasping mechanics, comparing the non-thumb fingers to a Venus flytrap that curls around objects based on resistance. "The big deal about the Belgrade hand was how it managed to take in and respond to feedback from the outside world to do precision movements." The author effectively uses this to illustrate how the device offloaded mental burden from the user, a concept that remains the holy grail of prosthetics today. However, the coverage also acknowledges the practical failures: the hand was too heavy, too bulky, and mechanically complex. "A clinical evaluation of this first hand identified drawbacks. The first Belgrade hand's mechanical complexity made it difficult to manage and its large external power system made it too heavy and bulky for practical use." This admission strengthens the piece's credibility, showing that innovation is often a messy, iterative process rather than a straight line to success.

The Lost Legacy of Artificial Reflexes

In the final section, Asianometry traces the lineage of Tomovich's ideas through the 1980s and 90s, where the philosophy of "Artificial Reflex Control" (ARC) was revisited but ultimately overshadowed by the rise of powerful microprocessors. The author notes that Tomovich and his collaborator George Bekey later built the Belgrade USC hand to prove that robots could grasp objects using reflex-like responses rather than complex top-down instructions. "They called it artificial reflex control or ARC. The Belgrade USC hand was intended to demonstrate that a robot hand can pick up and grasp items of varying size with just ARC principles rather than complex top-down instructions."

Despite the technical success, the commercial reality was harsh. The author points out that "in the commercial space, it was too complicated to compete against simple robot arm grippers." This serves as a sobering reminder that the most elegant biological solutions are not always the most economically viable. As the piece concludes, the author reflects on the enduring relevance of Tomovich's work: "It's a radical idea, one that continues to fascinate people and spur on future research to this day." The narrative suggests that as we move toward more autonomous systems, the industry may finally be ready to return to the biological principles Tomovich championed decades ago.

"Tomovich's north star, his biologically inspired theory of controlling robots via local reflex actions rather than complex top-down systems, remains a radical idea that continues to fascinate people and spur on future research to this day."

Bottom Line

Asianometry's coverage is a masterclass in connecting historical engineering to modern robotics challenges, successfully arguing that the Belgrade Hand's true legacy is its control philosophy rather than its physical form. The piece's greatest strength is its clear explanation of "error maximization," a concept that feels startlingly relevant in an era of AI hallucinations and rigid automation. However, the article could have explored more deeply why the industry abandoned this biological approach in favor of brute-force computing, leaving the reader to wonder if we are finally circling back to the right path or just repeating the same mistakes with better hardware.

Sources

High-five to the Belgrade hand

by Asianometry · Asianometry · Watch video

The human hand has 35 actuators or muscles for producing movement. 19 of which are inside the hand responsible for fine movements like bringing the fingers together or pulling them apart. The other 16 are located outside the hand but extend into it via tendons. These provide power for gripping and lifting.

Scientists can reproduce at least some of the hands physical elements and capabilities, but the rub has been controlled. How do we convey to the prosthetic all the complicated movements behind a quotequote simple gesture like grasping? In the early 1960s, a Yugoslav scientist from the well-known Maho Pupin Institute named Rako Tomovich looked to biology for a solution. He leveraged his findings to create arguably the first autonomous robotic hand.

Certainly the first such five-fingered robotic hand. And it was capable of precision tasks that might surprise you. In today's video, we profile a series of pioneering robotic prosthetics from communist Yugoslavia, the Belgrade hands. Tomovich was born in November 1919 in Baja, Hungary.

In 1936, his family settled in Bgrade where he did his secondary schooling. He then enrolled at the University of Bgrade to study electrical engineering, but those studies were interrupted by World War II. Tomovich joined the Yugoslav Communist Party and fought the Axis forces. He was arrested, sent to a forced labor camp, and for some time worked in a mine.

By the end of the war, he had risen to be a captain in the Yugoslav People's Army. After the wars end, he transferred back to the University of Bgrade to finish his studies. He earned his doctorate in the field of analog computers and then worked for a decade in Yugoslavia's nuclear research institute in Vinca. In 1960, Tomovich left, perhaps due to Tito halting the Yugoslav Nuclear Weapons Program.

He worked at UCLA in 1961 as a visiting scholar and then joined the Maho Pupin Institute. There he helped produce one of the country's first computers, the vacuum tube and transistor base CER10. After that he pivoted into work for developing prosthetics reportedly due to a desire to help injured World War II veterans. People have been making hand prosthetics since at least the days of the Roman Republic.

In 218 BC, the Roman general Marcus Sergius is said to have been fitted with an iron prosthetic that allowed him to hold a shield and fight battles against Hannibal ...