Implement in online ai2thor simulator

[liuxz-cs]

Hello, I try to train the model in online ai2thor simulator based on your algorithm, but it seems that it is very difficult to get good performance. I use resnet18 to get the feature of every observation the agent can get in ai2thor environment. I have trained the model using online ai2thor simulator, but the overall success rate of navigation is only about 9% in used scenes, when evaluating in unused scene, the performance is worse.

So I want to know the resnet18 structure you used to extracted the feature, maybe it's the problem. I use the pretrained resnet18 to extract the feature of observation, I add a nn.AdaptiveAvgPool2d layer after the conv5_x to get 512 x 7 x 7 feature, and then do action prediction.