求系统单位阶跃扰动响应的性能指标（超调量，峰值时间，调整时间），其中key=1表5 超调量key=2表2 的超调量，y，t表示系统节约相应的函数值与其对应时间-Demand system unit step disturbance response performance indicators (overshoot, peak time, adjusting the time), where key = 1 Table 5　overshoot key = 2 Table 2　overshoot, y, t that the system saves the corresponding The function value and its corresponding time