  With the Deep Neural Networks (DNNs) as a powerful function approximator,
Deep Reinforcement Learning (DRL) has been excellently demonstrated on robotic
control tasks. Compared to DNNs with vanilla artificial neurons, the
biologically plausible Spiking Neural Network (SNN) contains a diverse
population of spiking neurons, making it naturally powerful on state
representation with spatial and temporal information. Based on a hybrid
learning framework, where a spike actor-network infers actions from states and
a deep critic network evaluates the actor, we propose a Population-coding and
Dynamic-neurons improved Spiking Actor Network (PDSAN) for efficient state
representation from two different scales: input coding and neuronal coding. For
input coding, we apply population coding with dynamically receptive fields to
directly encode each input state component. For neuronal coding, we propose
different types of dynamic-neurons (containing 1st-order and 2nd-order neuronal
dynamics) to describe much more complex neuronal dynamics. Finally, the PDSAN
is trained in conjunction with deep critic networks using the Twin Delayed Deep
Deterministic policy gradient algorithm (TD3-PDSAN). Extensive experimental
results show that our TD3-PDSAN model achieves better performance than
state-of-the-art models on four OpenAI gym benchmark tasks. It is an important
attempt to improve RL with SNN towards the effective computation satisfying
biological plausibility.
