Robots make decisions in a variety of situations requiring multitasking. Therefore, in this work, a method is studied to address multiple tasks based on reinforcement learning. Our previous method selects an action when the q-values of the action for each task correspond to a priority value in the q-table. However, the decision-making would select an ineffective action in particular situations. In this study, an action value weighted by priority is defined (termed as action priority) to indicate that the selected action is effective in accomplishing the task. Subsequently a method is proposed for selecting actions using action priorities. It is demonstrated that the proposed method can accomplish tasks faster with fewer errors.

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