As robots increasingly operate in shared, safety critical environments, acting safely is no longer sufficient robots must also make their safety decisions intelligible to human collaborators. In human robot collaboration (HRC), behaviours such as stopping or switching modes are often triggered by internal safety constraints that remain opaque to nearby workers. We present a dialogue based framework for interactive explanation of safety decisions in HRC. The approach tightly couples explanation with constraint based safety evaluation, grounding dialogue in the same state and constraint representations that govern behaviour selection. Explanations are derived directly from the recorded decision trace, enabling users to pose causal ("Why?"), contrastive ("Why not?"), and counterfactual ("What if?") queries about safety interventions. Counterfactual reasoning is evaluated in a bounded manner under fixed, certified safety parameters, ensuring that interactive exploration does not relax operational guarantees. We instantiate the framework in a construction robotics scenario and provide a structured operational trace illustrating how constraint aware dialogue clarifies safety interventions and supports coordinated task recovery. By treating explanation as an operational interface to safety control, this work advances a design perspective for interactive, safety aware autonomy in HRC.

翻译：随着机器人在共享安全关键环境中的部署日益增多，仅实现安全行为已不足以保证协作效果——机器人还必须使其安全决策能够被人类协作者理解。在人机协作中，诸如停机或模式切换等行为往往由内部安全约束触发，而这些约束对现场工作人员而言是难以观测的。我们提出一种基于对话的框架，用于在HRC中实现安全决策的交互式解释。该方法将解释过程与基于约束的安全评估紧密结合，使对话机制植根于与行为选择相同的状态与约束表征体系中。解释内容直接从记录的决策轨迹中提取，支持用户对安全干预行为进行因果型（"为什么？"）、对比型（"为什么不是？"）和反事实型（"如果…会怎样？"）查询。反事实推理在固定且经认证的安全参数下以有界方式进行评估，确保交互探索不会削弱操作保障。我们将该框架应用于建筑机器人场景，并通过结构化操作轨迹展示：感知约束的对话机制如何阐明安全干预逻辑并支持协调式任务恢复。通过将解释视为安全控制的运行接口，本研究为HRC中具有交互感知能力的安全自主性提供了设计视角。