Define the environment
Specify continuous state and action spaces, reward function and termination conditions using a simulator such as Gymnasium or Mujoco.
Train a policy-gradient agent. Assess stability and safety.
Policy-gradient methods directly parameterise a policy and optimise expected return by following gradients estimated from trajectories. For continuous control they typically output continuous actions (e.g. Gaussian policies) and require careful tuning of baselines, variance reduction and reward shaping. Important failure modes include unstable training, sensitivity to hyperparameters, reward hacking and unsafe actions in real systems.
Learning concept · Not a validated service
Policy-gradient methods directly parameterise a policy and optimise expected return by following gradients estimated from trajectories. For continuous control they typically output continuous actions (e.g. Gaussian policies) and require careful tuning of baselines, variance reduction and reward shaping. Important failure modes include unstable training, sensitivity to hyperparameters, reward hacking and unsafe actions in real systems.
A proposed application: train a continuous-control policy for a simulated robotic arm and expose it through a human-in-the-loop dashboard so an operator can veto unsafe actions. This extension is a proposal; the supplied starter does not deliver a continuous-control policy or simulator integration.
Specify continuous state and action spaces, reward function and termination conditions using a simulator such as Gymnasium or Mujoco.
Use a parameterised policy (for example a Gaussian actor with a neural network mean) and a compatible optimiser in PyTorch.
Collect rollouts, compute discounted returns and apply a baseline or advantage estimator before updating policy parameters.
Track average return across seeds, variance of updates, and safety violations measured in the simulator; add human review for unsafe cases.
The supplied starter simulates a discrete multi-armed bandit with four Bernoulli arms. It uses an epsilon-greedy action selection and incremental sample-mean updates for estimated reward rates, then prints action counts, estimated rates and total reward. It does not implement a policy-gradient algorithm, continuous actions, trajectory collection, discounting or environment dynamics.
for step in range(1, 2001):
if rng.random() < epsilon:
action = rng.integers(len(true_reward_rates))
else:
action = int(np.argmax(estimated_values))
reward = 1 if rng.random() < true_reward_rates[action] else 0
action_counts[action] += 1
total_reward += reward
estimated_values[action] += (reward - estimated_values[action]) / action_counts[action]The code is a discrete multi-armed bandit experiment, not a policy-gradient implementation. It uses epsilon-greedy selection over four discrete arms and incremental sample means; there is no policy parameterisation, gradient estimation, continuous action handling or interaction with a Gym-like environment. Results therefore do not validate continuous-control methods.
Proposed extension: connect a Gymnasium continuous-control environment, implement a Gaussian actor (with or without a critic), collect trajectories, compute advantages and update the policy via a policy-gradient rule such as REINFORCE or PPO.
This is a potential application pathway, not a delivered product. The supplied starter does not implement this service or validate it with real users.
Networkers Home runs this topic inside its AI Engineer Course, with placement support and hands-on labs.