【正文】 us control theories. The design of controller is a main work of pendulum system. At present, the methods of controller design include: PID control, root locus and frequency respond, statespace method, optimal control theory and so on. The process of a controller design for the firstlevel inverted pendulum system is introduced. In this paper, a PID control and a pole assignment with statespace design are proposed. The Matlab software is used to carring out a program and simulation in the process of the controller design. The Mfile and simulink tool box are applied, and the result shows that these methods are effective. Form this paper, the controller designed by pole assignment with statespace is able to control the angle of pendulum bar and the location of handcart at the same time. The simulation shows that the method of statespace is better than traditional PID control algorithm.Key words: Inverted pendulum。 PID control。 Pole assignment。 Statespace Inverted pendulum control method in the field of military industry, aerospace, robot and general industrial process has a wide range of USES, such as the balance in the process of the robot control, verticality control of rocket and satellite attitude control are involved in flight inversion problem, therefore the research of inverted pendulum system which has profound significance in theory and methodology. Inverted pendulum is a typical quick, multivariable, nonlinear and absolutely unstable system. As early as the 1950 s, cybernetics expert at the Massachusetts institute of technology (MIT) is designed according to the principle of the booster rocket firstorder inverted pendulum experiment equipment, then the control method and train of thought in the field of military industry, aerospace, robot and has a wide range of USES, in the process of general industrial robot in the process of balance control, the verticality control, satellite rocket launcher of stability control, the plane landed safely, chemical process control, and had seen in the daily life of any focus on, the pivot of the next control problem, etc., are involved in inverted pendulum problem. In fact, people have been trying to find different ways to implement the control of the inverted pendulum control, in order to check or indicate that the method to control the serious nonlinear and absolutely unstable system. Inverted pendulum is ideal for automatic control teaching experiment equipment, it can fully meet the requirements of automatic control teaching. Many abstract concepts such as the control of system stability, controllability, convergence speed and system antiinterference ability, etc., can be displayed visually through the inverted pendulum. Due to the high order time inverted pendulum system, serious instability, multivariable, nonlinear and strong coupling features, attracted many scholars and researchers constantly explore new from the inverted pendulum control, control strategy and algorithm and applied to the fields of aerospace science and technology and the robot [2]. Many different kinds of inverted pendulum, a hanging inverted pendulum, a parallel inverted pendulum, annular inverted pendulum, planar inverted pendulum, and so on. Inverted pendulum series can be a level 1, level 2, level 3 and level 4, and multistage. Inverted pendulum motion track can be horizontal, can also be tilted (the actual robot walking stability control study more meaningful). Can be a single motor, control motor can also be a multistage motor. Because of the inverted pendulum system with bipedal robot, the rocket flight control, and all kinds of servo yuntai is very similar to a stable, so the study of inverted pendulum control mechanism has important theoretical and practical significance. Inverted pendulum system is a nonlinear, strong coupling, multivariable and natural unstable system. In the process of control, it can effectively reflect such as town can be qualitative, robust, followup and track, the key issues in many control is the ideal model for testing various control theories.In the process of the development of control theory, a theoretical correctness and feasibility of practical application need a according to its theory to design the controller to control a typical object to verify, inverted pendulum is a controlled object. The typicality of inverted pendulum is: as a experimental apparatus, low cost, simple structure, easy realization of analog and digital control of the two different ways。 As a controlled object, it is quite plicated, in and of itself, is a high order time, unstable, multivariable, nonlinear and strong coupling system, only by adopting effective control method can make the stability of [3]. To control the inverted pendulum system, its stable effect is very clear, can be directly through the swing Angle and displacement and stability time measurement, control and be clear at a glance. Theory is the pilot project, the research of inverted pendulum not only has its profound theoretical significance and has important engineering background. From everyday life to meet any of the center of gravity, the pivot of the next control problem, to the space vehicle and all kinds of the stability of servo yuntai, all have great similarity, and the control of the inverted pendulum is control of its stability in practice there are a lot of USES, such as the stability control of offshore drilling platform, the stability control of satellite launcher, rocket attitude control, the plane landed safely, chemical process control belong to this kind of problem. Therefore, the study of mechanism of inverted pendulum is of important theoretical and practical significance, has bee an enduring research subjects in the control theory.2. the main content and the main work done This design to inverted pendulum control system as the research object, using Matlab powerful numerical calculation and digital simulation, plete