Challenges in meta-reinforcement learning
The main challenges regarding meta-RL, following (Rakelly, 2019), are as follows:
- Meta-RL requires a meta-training step over various tasks, which are usually hand-crafted. A challenge here is to create an automated procedure to generate these tasks.
- The exploration phase that is supposed to be learned during meta-training is in practice is not efficiently learned.
- Meta-training involves sampling from an independent and identical distribution of tasks, which is not a realistic assumption. So, one goal is to make meta-RL more "online" by making it learn from a stream of tasks.
In addition to these challenges, it is important to note meta-RL methods will not work as well as the other methods, such as domain randomization, in complex tasks like robot hand manipulation. As the research in this area progresses, we can expect to see this gap to decrease and meta-RL make its way to mainstream with its unique advantages...