Equivalent transfer function method for PI/PID controller design of MIMO processes

In this paper, a novel design method for adaptive tracking control is proposed for robot finger dynamics. First, the dynamics are described by considering the robot finger as a large-scale system since it has many joints and multi-degrees of freedoms (DOFs). Second, by employing the direct adaptive fuzzy approximation method to approximate the unknown and desired control input signals instead of the unknown nonlinear functions, the number of adaptive design parameters obtained in the control design process is greatly reduced. Moreover, it is shown that the designed controller can guarantee all the signals in the closed-loop system to be semiglobally uniformly ultimately bounded. Finally, simulations are conducted on the Puma 560 robot manipulator, and the results show the effectiveness of the developed control design approach.

Decentralized Adaptive Fuzzy Tracking Control for Robot Finger Dynamics

A monitoring system, including an interface configured to communicate with a building device, a sensor, and a memory. The monitoring system includes a processor configured to communicate with the memory and the interface. The processor is configured to transmit a test signal to at least one of the building device and the sensor. The processor is further configured to receive a return signal from at least one of a building device signal and a sensor signal. Further, the processor is configured to associate the building device to the sensor based on the return signal.

Building automation systems and methods

In this article, two methods of designing a centralized control system for multi-input, multi-output (MIMO) processes are presented. Centralized proportional–integral (PI) controllers are designed based on a direct synthesis method. The inverse of the process transfer function matrix in the direct synthesis method is approximated based on the relative gain array concept. The method is further improved by using a relative normalized gain array, and an equivalent transfer function for each element in the process transfer function matrix is derived for the closed-loop control system. The transpose of the effective transfer function is used to approximate the inverse of the process transfer function matrix. The simulation studies demonstrate the effectiveness of this method. The proposed centralized controllers reduce the interactions better than recently reported decentralized controllers do. A centralized controller designed based on a relative normalized gain array (RNGA) gives a better performance than a centralized controller designed based on a relative gain array (RGA).

Centralized PI controllers for interacting multivariable processes by synthesis method.

In this article, a systematic approach is proposed to design PI-/PID-based multivariable control systems in which the designs and analyses of decentralized, decoupling, and sparse control schemes are all treated under a unified framework. First, based on the relative normalized gain array (RNGA), a best loop pairing is obtained using the RGA (relative gain array)−Nederlinski index (NI)−RNGA rules. The index matrix is then calculated, and the control structure is determined according to a selection criterion. Finally, the selected loop controllers are independently designed based on equivalent transfer functions. The effectiveness of the proposed design approach is verified by analysis of several multivariable industrial processes, demonstrating that the selected control structure results in better overall system performance.

Multivariable Process Control: Decentralized, Decoupling, or Sparse?

In this paper, a novel method for design of a decentralized control system for multivariable processes is proposed. On the basis of a new interaction measure, effective relative gain array (ERGA), in terms of energy transmission ratio, loop interactions are quantified by two elements, i.e., relative gain and relative critical frequency. The interaction effects for a particular loop from all other closed loops are analyzed through both steady-state gain and critical frequency variations. Consequently, appropriate detuning factors for decentralized controllers under different interaction conditions can be derived based on the effective relative gain, relative gain, and relative critical frequency. The design method can be effectively used for both normal processes as well as process-loop transfer functions containing unstable zeros resulted from other closed loops. This design method is simple, straightforward, and effective and can be easily understood and implemented by field engineers. Several multivaria...

and Mao-Jun He

Papers

Decentralized Control System Design for Multivariable ProcessesA Novel Method Based on Effective Relative Gain Array