A kinematic model of a self-replicating programmable constructing machine
To date, research into the implementation of autonomous self-replicating systems has focused either on highly abstract logical models, or on physical systems that are deliberately engineered in some way so as to make the problem more tractable . There are also several system-level proposals for physical self-replicating systems.
A simulation environment is presented at a level of abstraction that supports motion, connection and disconnection of parts, and which enforces the conservation of matter. This level of abstraction lies somewhere between cellular automaton models and real physical systems. The simulation environment is a 3D kinematic automaton in which cubic parts can be placed into a discrete space and connected together to make machines. The environment supports six part types:
A wire part receives a boolean input value at its base and propagates this value to all five of its outputs after one time unit.
A nor-gate part receives boolean input values from all five of its inputs, and propagates the logical NOR of these values to its output after one time unit.
A slide part receives a boolean input value from its input. If this value is true, then one time unit later it will move any part directly opposite its input.
A rotate part receives a boolean input value from its input. If this value is true then one time unit later it will rotate any part directly opposite its input.
A connect part receives a boolean input value from its input. If this value is true then one time unit later it will connect together the part lying opposite its input to a neighbouring part.
A disconnect part receives a boolean input value from its input. If this value is true then one time unit later it will disconnect the part lying opposite its input from a neighbouring part.
The simulation environment has previously been described in . A self-replicating programmable constructing machine (SRPC) with an architecture similar to that in  has been implemented in this environment. The machine can take a disorganised collection of parts as its input and construct machines from these parts according to a sequence of instructions.
As a special case, it can be programmed to construct a replica of itself. The machine is made from 59,504 parts, of which 49,152 make up the machine's memory. By demonstrating that an SRPC can be implemented in this environment, it is shown that some of the results already obtained about SRPCs in cellular automaton environments can be extended into the domain of kinematic systems, and also that consideration of the kinematical concepts of motion
and connectivity along with the conservation of matter does not introduce any barrier to the existence of such machines.
 Freitas and Merkle (2004), Kinematic Self Replicating Machines, Landes Bioscience
 Stevens (2009), Parts closure in a kinematic self-replicating programmable constructor, Artificial Life and Robotics 13(2) 508-511
 von Neumann and Burks (1966), Theory of Self-Reproducing Automata, Univ. of Illinois Press
Stevens, W. (2009, September). A kinematic model of a self-replicating programmable constructing machine. Poster presented at ECAL 2009 10th European Conference on Artificial Life, Budapest, Hungary
|Presentation Conference Type||Poster|
|Conference Name||ECAL 2009 10th European Conference on Artificial Life|
|Conference Location||Budapest, Hungary|
|Start Date||Sep 13, 2009|
|End Date||Sep 16, 2009|
|Publication Date||Jan 1, 2009|
|Publicly Available Date||Jun 8, 2019|
|Peer Reviewed||Peer Reviewed|
|Keywords||self-replication, self-replicating machine, kinematic automata|