Subpixel Estimation

Fisher, Robert B.

doi:10.1007/978-3-030-63416-2_189

Cited by 4 publications

(2 citation statements)

References 17 publications

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“…The images were scaled using the ball diameter as reference length, and the spatial resolution was 3.5 pixels/mm. Even though a sub-pixel accuracy on the order of ± 0.1 pixels is rather common for centroid location [32], it seems prudent to assume here a more conservative accuracy estimate of ± 1 pixel for the ball centroid location, corresponding to about ± 300 microns, because the present position tracking methodology was conceived to be costeffective and hence was not optimized.…”

Section: Motion Tracking Methodologymentioning

confidence: 99%

A Cost-Effective Integrated Methodology for Electromagnetic Actuation via Visual Feedback

Chen,

Padovani,

Cioncolini

et al. 2024

Preprint

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Electromagnetic actuation can support many fields of technology, such as robotics or biomedical applications. In this context, fully understanding the system behavior and proposing a low-cost package for feedback control is challenging. Modeling the electromagnetic force is particularly tricky because it is a nonlinear function of the actuated object’s position and coil’s current. Measuring in real time the position of the actuated object with the precision required for accurate motion control is also nontrivial. In this study, we propose a novel, cost-effective electromagnetic set-up to achieve position control via visual feedback. We actuate vertically and under different experimental conditions a 10 mm diameter steel ball hanging on a low-stiffness spring, demonstrating good tracking performance (the position error remains within ±0.5 mm with a negligible phase delay in the best scenarios). The experimental results confirm the feasibility of the proposed set-up, which is characterized by minimum complexity and realized with off-the-shelf and cost-effective components. For these reasons, such a contribution helps to understand and apply electromagnetic actuation even further.

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Section: Motion Tracking Methodologymentioning

confidence: 99%

A Cost-Effective Integrated Methodology for Electromagnetic Actuation via Visual Feedback

Chen,

Padovani,

Cioncolini

et al. 2024

Preprint

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“…Quantization as a result of discrete pixel disparity values limits the achievable depth accuracy, although sub-pixel estimation can enable resolving disparity to less than a single pixel value [22]. Stereo depth accuracy ∆𝑧 is derived in Equation ( 2), revealing the squared increase in error with distance characteristic of stereo depth.…”

Section: 𝑧 𝑓 𝐵 𝑑mentioning

confidence: 99%

Guided Direct Time-of-Flight Lidar Using Stereo Cameras for Enhanced Laser Power Efficiency

Taneski,

Gyongy,

Al Abbas

et al. 2023

Sensors

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Self-driving vehicles demand efficient and reliable depth-sensing technologies. Lidar, with its capability for long-distance, high-precision measurement, is a crucial component in this pursuit. However, conventional mechanical scanning implementations suffer from reliability, cost, and frame rate limitations. Solid-state lidar solutions have emerged as a promising alternative, but the vast amount of photon data processed and stored using conventional direct time-of-flight (dToF) prevents long-distance sensing unless power-intensive partial histogram approaches are used. In this paper, we introduce a groundbreaking ‘guided’ dToF approach, harnessing external guidance from other onboard sensors to narrow down the depth search space for a power and data-efficient solution. This approach centers around a dToF sensor in which the exposed time window of independent pixels can be dynamically adjusted. We utilize a 64-by-32 macropixel dToF sensor and a pair of vision cameras to provide the guiding depth estimates. Our demonstrator captures a dynamic outdoor scene at 3 fps with distances up to 75 m. Compared to a conventional full histogram approach, on-chip data is reduced by over twenty times, while the total laser cycles in each frame are reduced by at least six times compared to any partial histogram approach. The capability of guided dToF to mitigate multipath reflections is also demonstrated. For self-driving vehicles where a wealth of sensor data is already available, guided dToF opens new possibilities for efficient solid-state lidar.

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Guided Direct Time-of-Flight Lidar using Stereo Cameras for Enhanced Laser Power Efficiency

Taneski,

Gyongy,

Abbas

et al. 2023

Preprint

View full text Add to dashboard Cite

Self-driving vehicles demand efficient and reliable depth sensing technologies. Lidar, with its capacity for long-distance, high-precision measurement, is a crucial component in this pursuit. However, conventional mechanical scanning implementations suffer from reliability, cost, and frame rate limitations. Solid-state lidar solutions have emerged as a promising alternative, but the vast amount of photon data processed and stored using conventional direct time-of-flight (dToF) prevents long-distance sensing unless power-intensive partial histogram approaches are used. In this paper, we introduce a groundbreaking ‘guided’ dToF approach, harnessing external guidance from other onboard sensors to narrow down the depth search space for a power and data-efficient solution. This approach centers around a dToF sensor in-which the exposed time widow of independent pixels can be dynamically adjusted. We utilize a 64-by-32 macropixel dToF sensor and a pair of vision cameras to provide the guiding depth estimates. Our demonstrator captures a dynamic outdoor scene at 3 fps with distances up 75 m. Compared to a conventional full histogram approach, on-chip data is reduced by over 25 times, while the total laser cycles in each frame are reduced by at least 6 times compared to any partial histogram approach. The capability of guided dToF to mitigate multipath reflections is also demonstrated. For self-driving vehicles where a wealth of sensor data is already available, guided dToF opens new possibilities for efficient solid-state lidar.

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Subpixel Estimation

Cited by 4 publications

References 17 publications

A Cost-Effective Integrated Methodology for Electromagnetic Actuation via Visual Feedback

A Cost-Effective Integrated Methodology for Electromagnetic Actuation via Visual Feedback

Guided Direct Time-of-Flight Lidar Using Stereo Cameras for Enhanced Laser Power Efficiency

Guided Direct Time-of-Flight Lidar using Stereo Cameras for Enhanced Laser Power Efficiency

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