A review of bottom up robotics

In the late 1980s there was a fundamental paradigm shift available in the domain of Artificial Intelligence, called bottum up robotics or subsumption architecture. It wasn't a new algorithm but at first it was a criticism of AI in the past. Bottom up robotics is mostly the description that program controlled top down robotics until the year 1990 has failed. Instead Brooks recommended to build simple sensor driven robots in the style of William Walter's turtle robot in the 1940s.

In a single sentence, Brooks argued, that its unclear how to program robots and instead of trying it harder, the answer is to give up and build instead Analog beam robots with a single sensor and a single motor. Of course, such a robot doesn't make sense because the goal is to build high complex machines which can do practical tasks and not to build a light following bug which can't do anything.

Despite of this step backward, bottom up robotics had become a great success. Many other researchers have agreed to Brooks, and similar architectures like Tilden's BEAM robots were popular.

Let us describe bottom up robotics from a birds eye perspective. These robots or artificial bugs are mostly controlled by its environment and by a random generator but not by an internal program. This paradigm shift was the real novelty of Brooks. It introduced a concept in which the former program oriented approach in robotics was dismissed in favor of external control.

Brooks identified correctly what sort of technology can't be realized. Its not possible to program a robot similar to a computer program. It doesn't make sense to write a C program and compile it for a microcontroller which is doing something with a robot because such a C program will provide a reality gap to the environment. A high complex task will require a high complex computer program and nobody knows who to write down the source code.

Let me give an example. Before the advent of bottom up robotics, the shared assumption in artificial intelligence was, that a robot who should grasp an objects needs to be programmed first. There are 5000 lines of code which are planning the grasping, solving the mathematical equation to determine the trajectory of the gripper and monitor if the robot is successful. Its impossible to write and improve such a C program.