This paper considers the problem of simultaneously controlling an interceptor's impact time and impact angle using its lateral acceleration as the sole control input. With a single control input, the nonlinear engagement kinematics is inherently underactuated, which complicates guidance law synthesis. To overcome this challenge, a hierarchical sliding mode-based guidance law is developed to concurrently regulate the two terminal constraints. The proposed architecture consists of a two-layer sliding manifold. The first layer comprises two sub-sliding surfaces corresponding to the impact time and impact angle error dynamics, respectively, while the second layer introduces a composite sliding manifold that combines the two individual sub-surfaces. Then, a variable-gain adaptive guidance law is designed to ensure time and angle-constrained interception against a stationary target, which is further extended to intercept a constant velocity target. Simulations are conducted for various engagement scenarios to attest to the efficacy of the proposed approach.

翻译：本文研究了仅利用拦截器横向加速度作为单一控制输入，同时控制其撞击时间和撞击角度的问题。在单一控制输入下，非线性交战运动学本质上具有欠驱动特性，这增加了制导律设计的复杂性。为克服这一挑战，本文提出了一种基于分层滑模的制导律，以同时调节两个终端约束。所提出的架构由两层滑模流形构成：第一层包含分别对应撞击时间和撞击角度误差动态的两个子滑模面；第二层引入了一个组合两个独立子滑模面的复合滑模流形。随后，设计了一种变增益自适应制导律，以实现针对固定目标的时角约束拦截，并进一步扩展至拦截匀速运动目标。针对多种交战场景进行了仿真，以验证所提方法的有效性。