Design For The Constant Tension System Based On Embedded System

Nowadays in china, the deep space detection technology development is in constant depth. There will be more and more spacecrafts which were sent up into space or into the planet, and the kind of spacecrafts will be mainly from the satellite with little motion characteristics to some robot with more motion characteristics. So, it is important to evaluate the motion characteristics of the spacecraft by provide the gravity environment similar to the outer space to the craft on the earth.The usual practice is to use a low-gravity simulation device to simulate the low-gravity environment for the craft. The type of sling using low-gravity simulator is competent to testing the motion characteristics of the spacecraft, because it works with no time limit and no size limit. In the type of sling using low-gravity simulator, the sling is directly connected to the spacecraft, it provides the tension in the vertical direction, its vertical direction track is particularly important. The project is come from one of China Aerospace Science and Technology’s projects, and aim to design and make a set of system which can provide both the permanent tension and tracking vertical motion of the spacecraft.The sling part is directly driven by torque motor. So the control of motor become so important. This paper mainly has two aspects to solve the problem of controller design.: one is the modeling of the system. Using equivalent physics model to establish which is to practical system and easy for controller design model is crucial.For cable components in the system, respectively, using the equivalent stiffness, equivalent elastic,equivalent infinitesimal element method model to approximate the actual system; the second is the controller design. The controller design is base on the established model.as the projects to applied to embedded system, so the controller is best to be simple. In this paper, the frequency domain method is used to control the model two and model three.To implement the project, the traditional controller implementation scheme is using computer and electronic board. This scheme has been favored because of the friendly interface, real-time, and convenient development. But it also has some defects.Including the confidentiality of security caused by the process of consideration, the system is too large, inconvenient to move, can be extended to control the type of board.This paper will make a new embedded controller, the controller uses a powerful processing chip, so that it has a strong computing power and computing speed.Uses fender structure board in floor, the functional coupling between different PCB circuit board do minimum, to board the expansion.In addition, the project board will join a variety of input and output interfaces, including CAN, AD/DA, IO, PROFIBUS,Ethernet, serial port and so on, so that the control board of the general.