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Frame synchronization of high-speed vision sensors with respect to temporally encoded illumination in highly dynamic environments.

Hou L, Kagami S, Hashimoto K - Sensors (Basel) (2013)

Bottom Line: Based on signal normalization, Manchester Encoded reference signals carry temporal information owing to serial communication and thus can timestamp the output vision frame.Both simulated and experimental results show satisfactory robustness to various disturbances, such as dynamic targets, fluctuant optical intensity, and unfixed cameras, etc.This result is believed to be applicable to low-cost wireless vision sensor network.

View Article: PubMed Central - PubMed

Affiliation: Department of Automation, Shanghai Jiao Tong University, and Key Laboratory of System Controland Information Processing, Ministry of Education of China, Shanghai 200240, China. lei@ic.is.tohoku.ac.jp

ABSTRACT
The authors propose a Manchester Encoding inspired illumination modulation strategy to properly index the temporally-aligned vision frames, which are successfully synchronized by the LED reference signal. Based on signal normalization, Manchester Encoded reference signals carry temporal information owing to serial communication and thus can timestamp the output vision frame. Both simulated and experimental results show satisfactory robustness to various disturbances, such as dynamic targets, fluctuant optical intensity, and unfixed cameras, etc. The 1,000 Hz vision sensor is locked to 500 Hz temporally modulated LED illumination with only 24 μs jitters. This result is believed to be applicable to low-cost wireless vision sensor network.

No MeSH data available.


Simulation results, (a) q̅2(t), (b) normalizer.
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f9-sensors-13-04102: Simulation results, (a) q̅2(t), (b) normalizer.

Mentions: The gain Gp was set to 64, and Gi was set to 1. Figure 8(b) shows the time correlation value of the output signal g1(t), and Figure 9(a) shows the correlation of g2(t). Figure 9(b) shows the normalizer. Figure 10 shows the relative phase between f(t) and g1(t). It can be seen that the system immediately converged to the π/2 relative phase and became stable thereafter. Apparently, the PI feedback helps to reduce the discrepancy between π/2 and the real phase, which corresponds to the steady-state error.


Frame synchronization of high-speed vision sensors with respect to temporally encoded illumination in highly dynamic environments.

Hou L, Kagami S, Hashimoto K - Sensors (Basel) (2013)

Simulation results, (a) q̅2(t), (b) normalizer.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3673073&req=5

f9-sensors-13-04102: Simulation results, (a) q̅2(t), (b) normalizer.
Mentions: The gain Gp was set to 64, and Gi was set to 1. Figure 8(b) shows the time correlation value of the output signal g1(t), and Figure 9(a) shows the correlation of g2(t). Figure 9(b) shows the normalizer. Figure 10 shows the relative phase between f(t) and g1(t). It can be seen that the system immediately converged to the π/2 relative phase and became stable thereafter. Apparently, the PI feedback helps to reduce the discrepancy between π/2 and the real phase, which corresponds to the steady-state error.

Bottom Line: Based on signal normalization, Manchester Encoded reference signals carry temporal information owing to serial communication and thus can timestamp the output vision frame.Both simulated and experimental results show satisfactory robustness to various disturbances, such as dynamic targets, fluctuant optical intensity, and unfixed cameras, etc.This result is believed to be applicable to low-cost wireless vision sensor network.

View Article: PubMed Central - PubMed

Affiliation: Department of Automation, Shanghai Jiao Tong University, and Key Laboratory of System Controland Information Processing, Ministry of Education of China, Shanghai 200240, China. lei@ic.is.tohoku.ac.jp

ABSTRACT
The authors propose a Manchester Encoding inspired illumination modulation strategy to properly index the temporally-aligned vision frames, which are successfully synchronized by the LED reference signal. Based on signal normalization, Manchester Encoded reference signals carry temporal information owing to serial communication and thus can timestamp the output vision frame. Both simulated and experimental results show satisfactory robustness to various disturbances, such as dynamic targets, fluctuant optical intensity, and unfixed cameras, etc. The 1,000 Hz vision sensor is locked to 500 Hz temporally modulated LED illumination with only 24 μs jitters. This result is believed to be applicable to low-cost wireless vision sensor network.

No MeSH data available.