Modular Reinforcement Learning

Reinforcement learning is a framework to maximize cumulative future reward that the agent gets through interaction with the environment. It is usually assumed that prior information about the dynamics and reward are not available, which makes learning very slow. An essential issue in reinforcement learning is how learning can be accelerated by using internal models or by imitation of other agents.

Generally, the environment is non-stationary and complex, and hard to approximate for a single controller. One solution is to use multiple forward and reward models of the environment. Each forward and reward model makes a local approximation of the dynamics and reward function.

For the proposed algorithm (?), we tested the performance for a non-linear, non-stationary cart-pole task. For t=0-2 s the peak of the reward function was z=10 m, then the peak moves to z=-10m. Fig. 1 shows the trajectory of the cart-pole. The color of the cart represents a particular (?) reward model. Next, we try for the acrobot swingup task, which has a strong non-linearity. Fig. 2. shows the results. Despite the strong non-inearity, the agent could succesfully learn to swing up.