| Offshore oil and gas fields are located in the shoals of bad environment. The operation on the plant needs worker in the field.And it is dangerous and low real-time. To tackle these problems, we build oil field automation system, in order to achieve automation on the oil field. For that it’s difficult to arrange wire in the field, we lead in network control system (NCS) based on wireless network, which is no wire, structural flexibility, easy system expansion, easy maintenance, sharing of information. But due to leading in the wireless network control system, random long delay comes in which will affect the control performance of the control system. To compensate random long network-induced delay, this paper mainly has two aspects which are the analysis of the delay and the design of the compensation controller of the delay.First, we analyze the composition of the network-induced delay and its affection on the control performance of the control system which is simulated.Secondly, we study the compensation controller of the delay, including the study of the fast implicit generalized predictive control algorithms (GPC) and the time-delay compensation algorithm based on fast implicit GPC. For heavy calculation burden for solving the Diophantine equation and inverse matrix in the generalized predictive control, an improved generalized predictive control algorithm is proposed in this paper, which does not need to solve the Diophantine equation and inverse matrix. The simulation results show the effectiveness of the algorithm.Thirdly, on the basis of the location of actuators and sensors, we give the time-delay compensation algorithm based on the fast implicit generalized predictive control algorithm. If actuator and sensor are in the same device, the time-delay compensation algorithm based on time stamp is proposed. And when actuator and sensor are not in the same device, the new time-delay compensation algorithm is proposed. In the algorithm, assuming that the controller is clock-driven, we establish buffer zones in the controller and actuator for network-induced delay compensation. Simulation results validate the effectiveness of proposed methods.Finally, on the basis of the two time-delay compensation algorithms, the time-delay compensation algorithm based on rapid response GPC is proposed. It can reduce the regulation time and inhibit the overshoot. And simulation results validate the effectiveness of proposed methods. |
