During control from the Flight Control Center (see Figure 1.2) information and commands are issued and received by a whole complex of on-board and Earth- based equipment. After automatic processing, the information enters the monitoring and control panel of the on-duty operators, including docking system specialists in the control and analysis group. 1.4. Initial Docking Conditions In docking the spacecraft approach each other so that the docking assemblies are maintained in a coaxial position. A specific longitudinal and zero velocity is held in the remaining linear and angular coordinates [14, 15]. Naturally, the parameters of relative motion have a scatter which is defined by the properties of the measurement equipment for relative position and velocity, and by the characteristics of the control systems. Possible values of relative coordinates which define the deviation from a coaxial position and their first derivatives during mechanical contact (Figure 1.3) are called the initial docking conditions, and define one of the main technical requirements for planning and testing docking devices. The relative position and velocity of gradual shifting are usually maintained using the motion control system of the active spacecraft, and orientation and stabilization (rotation around the centers of mass) of both spacecraft. In fully automatic control, radar systems are used, and these measure the relative linear and angular coordinates and their derivatives. When the crew is participating in the control, optical visors and television cameras are used on the active spacecraft, as well as targets and spatial optical indices on the passive spacecraft (see Figures 1.1 and 1.4). These targets make it possible to measure both linear and angular deviations of the spacecraft from a coaxial position. The coaxial position of the visors and targets, as well as the matching antennas of the radar devices, agrees with the coaxial position of the docking assembly. Observing the target on the screen of the visor, the pilot of the active spacecraft, using two three-stage control sticks affects the executive organs of the craft to maintain the coaxial approach with the passive craft at a given speed. In the approach the passive spacecraft maintains angular stabilization, and, when there is an automatic radar, its orientation on the active spacecraft. The
RkJQdWJsaXNoZXIy MTU5NjU0Mg==