We propose a 2D simulation system for multi-agent collective construction (MACC) based on simple line-following intelligent machines (SLIM) - small differential drive mobile robots. Our MACC-SLIM system alleviates the high upfront cost of implementing MACC on real hardware. Our system builds upon widely available resources, namely a standard LCD screen and commodity mobile robots, allowing researchers and schools easier access to MACC hardware implementation. We test the system on plans generated by an optimal state-of-the-art MACC algorithm, demonstrating there are still non-insignificant synchronization delays. The MACC-SLIM system allows us to observe bottlenecks, parallelism, and possible execution failures of plans generated by the MACC algorithms.

We propose a new approach for multi-agent collective construction, based on the idea of reversible ramps. Our ReRamp algorithm utilizes reversible side-ramps to generate construction plans for ramped block structures higher and larger than was previously possible using state-of-the-art planning algorithms, given the same building area. We compare the ReRamp algorithm to similar state-of-the-art algorithms on a set of benchmark instances, where we demonstrate its superior computational speed. We also establish in our experiments that the ReRamp algorithm is capable of generating plans for a single-story house, an important milestone on the road to real-world multi-agent construction applications.