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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.


Block Diagram of PLL with PI controller.
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f7-sensors-13-04102: Block Diagram of PLL with PI controller.

Mentions: To remove the steady-state residual phase error caused by frequency mismatch, a PI (proportional-integral) controller is added to PLL as shown in Figure 7. An integral term is added to Equation (8) as(8)τnonint[i]=τ0+Gp⋅q1[i]max(/q1[i]/,/q2[i]/)+Gi∑j=0∞q1[i−j]max(/q1[i−j]/,/q2[i−j]/)where τ0 is a constant set to 0.2 ms, and Gp and Gi are constant values optimized by simulation. The adjustment resolution of τnonint is 100 ns, which is the instruction cycle of the proposed vision sensors.


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)

Block Diagram of PLL with PI controller.
© Copyright Policy
Related In: Results  -  Collection

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

f7-sensors-13-04102: Block Diagram of PLL with PI controller.
Mentions: To remove the steady-state residual phase error caused by frequency mismatch, a PI (proportional-integral) controller is added to PLL as shown in Figure 7. An integral term is added to Equation (8) as(8)τnonint[i]=τ0+Gp⋅q1[i]max(/q1[i]/,/q2[i]/)+Gi∑j=0∞q1[i−j]max(/q1[i−j]/,/q2[i−j]/)where τ0 is a constant set to 0.2 ms, and Gp and Gi are constant values optimized by simulation. The adjustment resolution of τnonint is 100 ns, which is the instruction cycle of the proposed vision sensors.

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.