TY - JOUR
T1 - Adaptive vision-based guidance law with guaranteed performance bounds
AU - Ma, Lili
AU - Cao, Chengyu
AU - Hovakimyan, Naira
AU - Dobrokhodov, Vladimir
AU - Kaminer, Isaac
N1 - Funding Information:
The work was sponsored in part by the U.S. Army Research Office grant W911NF-06-1-0330 and U.S. Air Force Office of Scientific Research Multidisciplinary University Research Initiative subcontract F49620-03-1-0401. Authors from the Naval Postgraduate School acknowledge the support of the U.S. Special Operations Command.
PY - 2010
Y1 - 2010
N2 - This work discusses vision-based tracking of a ground vehicle moving with unknown time-varying velocity. The follower unmanned aerial vehicle is equipped with a single camera. The control objective is to regulate the twodimensional horizontal range between the unmanned aerial vehicle and the target to a constant. The contribution of this paper has two distinct features. The developed guidance law uses the estimates of the target's velocity obtained from a fast-estimation scheme. It is shown that the fast-estimation scheme has guaranteed performance bounds and the tracking performance bound can be explicitly derived as a function of the estimation error. The performance bounds imply that the signals of the closed-loop adaptive system remain close to the corresponding signals of a bounded closed-loop reference system, both in transient and steady-state responses. The reference system is introduced solely for the purpose of analysis. This paper also analyzes the stability and the performance degradation of the closed-loop adaptive system in the presence of out-of-frame events, when continuous extraction of the target's information is not feasible due to failures in the image-processing module. The feedback loop is then closed using the frozen estimates. The out-of-frame events are modeled as brief instabilities. A sufficient condition for the switching signal is derived that guarantees graceful degradation of performance during target loss. The results build upon the earlier-developed fast-estimation scheme of the target's velocity, the inverse-kinematics-based guidance law, and insights from switching systems theory.
AB - This work discusses vision-based tracking of a ground vehicle moving with unknown time-varying velocity. The follower unmanned aerial vehicle is equipped with a single camera. The control objective is to regulate the twodimensional horizontal range between the unmanned aerial vehicle and the target to a constant. The contribution of this paper has two distinct features. The developed guidance law uses the estimates of the target's velocity obtained from a fast-estimation scheme. It is shown that the fast-estimation scheme has guaranteed performance bounds and the tracking performance bound can be explicitly derived as a function of the estimation error. The performance bounds imply that the signals of the closed-loop adaptive system remain close to the corresponding signals of a bounded closed-loop reference system, both in transient and steady-state responses. The reference system is introduced solely for the purpose of analysis. This paper also analyzes the stability and the performance degradation of the closed-loop adaptive system in the presence of out-of-frame events, when continuous extraction of the target's information is not feasible due to failures in the image-processing module. The feedback loop is then closed using the frozen estimates. The out-of-frame events are modeled as brief instabilities. A sufficient condition for the switching signal is derived that guarantees graceful degradation of performance during target loss. The results build upon the earlier-developed fast-estimation scheme of the target's velocity, the inverse-kinematics-based guidance law, and insights from switching systems theory.
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U2 - 10.2514/1.46287
DO - 10.2514/1.46287
M3 - Article
AN - SCOPUS:77953758418
SN - 0731-5090
VL - 33
SP - 834
EP - 852
JO - Journal of Guidance, Control, and Dynamics
JF - Journal of Guidance, Control, and Dynamics
IS - 3
ER -