Multi-rate tracking controller analysis and design for target tracking systems

Abstract

As the sampling rates of the inner loop and the outer loop of the target tracking control system are different, a typical digital multi-rate control system was formed. If the traditional single-rate design method was applied, the low sampling rate loop will seriously impact the dynamical characteristic of the system. After analyzing and calculating the impact law of the low sampling rate loop to the bandwidth and the stability of the tracking system, a kind of multi-rate control system design method was introduced. Corresponding to the different sampling rates of the inner loop and the outer loop, the multi-rate control strategy was constituted by a high sampling rate sub-controller and a low sampling rate sub-controller. The two sub-controllers were designed separately and connected by means of the sampling rate converter. The low sampling rate controller determined the response rapidity of the system, while the high sampling rate controller applied additionally effective control outputs to the system during a sampling interval of the low sampling rate controller. With the introduced high and low sampling rates sub-controllers, the tracking control system can achieve the same performance as a single-rate controller with high sampling rate, yet it works under a much lower sampling rate. The simulation and experimental results show the effectiveness of the introduced multi-rate control design method. It reduces the settling time by 5 times and the over shoot by 4 times compared with the PID control.

Keywords

multi-rate control / system delay / target tracking control

References

[1] ZhangW-boA study on working mechanism and advanced measurement &control method of seeker servo equipment [D], 2008ChangshaNational University of Defense Technology127-132

[2] AntonioS, JulianJ S. Frequency response of discrete dual-rate systems [C]. The Second International Conference on Advanced Engineering Computing and Applications in Sciences, 2008ValenicaIEEE Press129-134

[3] MaA-h, ZhouL-fang. Analysis of multi-rate predictive control systems [J]. Computers and Applied Chemistry, 2010, 27(1): 77-81

[4] ChodosS L. Track loop bandwith, sensor sample frequency and track loop delays [C]. Proc. SPIE 3365, Acquistion, Tracking and Pointing XII, 1998Orlando, USASPIE69-76

[5] AnsariH. Digital control design of a CCD-based tracking loop for precision beam pointing [C]. Proc. SPIE 2123, Free-space Laser Communication Technolagies VI, 1994Los Angeles, USASPIE328-333

[6] CiminoM, PagillaP R. Design of linear time-invariant controllers for multirate system [J]. Automatica, 2010, 46: 1315-1319

[7] OzdemirN, TownleyS. Integral control by variable sampling based on steady-state data [J]. Automatica, 2003, 39: 135-140

[8] KawakitaM, YubaiK, HiraiJ. The multi-rate sampling control for a reconfigurable robot [C]. 11th International Conference on Control, Automation and Systems, Gyeonggi-do, 2011KoreaIEEE Press516-521

[9] HattoriY, SatoT, ArakiN, KonishiY. A design method for a multi-rate control system in state-space approach [C]. Proceedings of the 2010 International Conference on Modeling, Identification and Control, Okayama, 2010JapanIEEE Press264-268

[10] ZhangW-c, LiL, ShiZ-guo. Multirate self-tuning control [C]. 4th IEEE Conference on Industrial Electronics and Application, 2009Xi’anIEEE Press387-392

[11] ZhouL-f, MaA-l, LiuL-l, ZhuN-na. The analysis of optimal sampling period on output multi-rate predictive control system. 2010 Chinese Control and Decision Conference, 2010XuzhouIEEE Press1102-1105

[12] MaC-y, LiuX-h, GaoRong. A direct robust predictive control algorithm for multi-rate systems [C]. Proceedings of the 30th Chinese Control Conference, 2011Yantai, ChinaIEEE Press3357-3361

[13] BarcelliD, BemporadA, RipaccioliG. Hierarchical multi-rate control design for constrained linear systems [C]. 49th IEEE Conference on Decision and Control, 2010Atlanta, GA, USAIEEE Press5216-5221

[14] FengX-q, YangW-shu. Study on the method of improving the sampling control system bandwidth [J]. Optoelectronic Engineering, 2003, 30(4): 20-23

[15] TorneroJ, GuY, TomizukaM. Analysis of multi-rate discrete equivalent of continuous controller [C]. Proceeding of the American Control Conference, 1999San Diego, USAIEEE Press2759-2763

[16] SaltJ, AlbertosP. Multi-rate controllers design by rate decomposition [C]. Proceedings of the 39th IEEE Conference on Decision and Control, Sydney, 2000AustraliaIEEE Press4895-4900