A reach-avoid differential game with two evaders and one pursuer is considered in the plane which is divided into a play region and a goal region by a straight line. Two evaders, starting from the play region, aim at reaching the goal region protected by the faster pursuer who tries to capture the evaders. This game is analysed from kind and degree in analytical forms. The information structure involves that the evaders know which one is being pursued by the pursuer while the pursuer has access to the evaders' current control inputs. We are concerned with the barrier and winning regions, by which the number of evaders reaching the goal region before being captured can be determined. Cooperative strategies for two evaders are derived based on the goal priority between team goal and individual goal. An Apollonius circle based pursuit strategy is explicitly proposed. The δ-Apollonius circle is introduced to handle with the pursuit of the second-pursued evader. When two evaders are both possible to be captured, motivated by the cooperation between two prey animals against a predator, an aiding strategy is proposed such that one evader sacrifices itself to help the other's evasion. Numerical simulations are presented.

在由直线划分为游戏区域和目标区域的平面中考虑具有两个躲避者和一个追击者的到达-避免差分博弈。两名躲避者，从游戏区域出发，目标是到达试图抓住躲避者的较快追击者保护的目标区域。这个游戏是从种类和程度的分析形式来分析的。信息结构涉及逃避者知道追捕者正在追捕哪一个，而追捕者可以访问逃避者的当前控制输入。我们关注屏障和获胜区域，通过它们可以确定在被捕获之前到达目标区域的逃避者数量。两个逃避者的合作策略是基于团队目标和个人目标之间的目标优先级推导出来的。明确提出了基于 Apollonius 圆的追击策略。这引入δ-阿波罗尼乌斯圆来处理第二追逃者的追击。当两个逃避者都可能被捕获时，出于两个猎物之间的合作对抗捕食者的动机，提出了一种援助策略，使得一个逃避者牺牲自己来帮助另一个逃避。给出了数值模拟。