Time and angle constraint three-dimensional sliding mode guidance law design method under uncontrollable speed condition

The invention relates to a time and angle constraint three-dimensional sliding mode guidance law design method under the condition of uncontrollable speed, and relates to the technical field of missile guidance. The designed guidance law is perpendicular to the speed direction, and the expected attack time and attack angle are achieved only by changing the speed direction of the missile. In a pitching channel, a rapidly convergent non-singular sliding mode surface and a sliding mode reaching law changing along with the missile distance are provided, and the expected sight line elevation angle is achieved; in a yaw channel, a special sliding mode surface is designed by analyzing guidance conditions of the yaw channel, and a missile can reach the sliding mode surface through a superhelix sliding mode theory, so that an expected sight azimuth angle and expected attack time are realized. Under the condition that the missile speed is uncontrollable, the missile hits the target at the expected attack time and the a