Calculation of swing angle involves in calculating the precise distance from the base to the particular object. Depth calculation with monocular camera will not be accurate enough for this particular purpose. Even the stereo camera, the accuracy will be dropped with the distance from the camera. Far the distance causes less accuracy. Mounting two monocular cameras far away but pointing to a particular point may able to achieve the required accuracy in distance calculation but, it may not able to detect near by details. Placing the camera somewhere in the middle of the site would be a solution but still it requires re-calibration when ever the crane base is moved. Most of the RGBD cameras are having much less depth resolution than the requirement in this kind of projects. My suggestion is to use two monocular camera mounted at reasonably away from each other to capture the scene and to calculate the depth, which will do the job for most of the time. Otherwise use an accurate range finder attached to a rotatable platform, to work with the other cameras for accurate swing angle calculation.

Thanks. Our ultimate goal is to use only Machine Vision for detecting swing angle, obstacle avoidance. So, range finder due to a higher cost is not ultimate goal. Any suggestions of any model of high quality monocular cameras that can be use for these purpose?

When ever I select a camera for any of my computer vision related projects first I obtain the following factors which works best for the problem.

A. FOV

B. Distance (in your case 40m)

C. Sensor resolution: This should be calculated using the FOV, object distance and the required accuracy in depth calculation.

D. Lighting conditions: (Auto exposure works good only in outdoor and day time operations. Otherwise select a camera which supports manual exposure setting)

E. Communication interface: Based on ambient noise, bandwidth requirement, processing location and processing equipment compatibility.

F. Lens: based on FOV

G. Spectral options (for selecting filters)

I. FPS: 15 would be enough for static obstacle modeling. But at least 30 is required for real-time tracking (if you are going to do adjustments to the swing, dynamically)

J. Sensor type: to avoid certain effects such as rolling shutter and considering spectral sensitivity.

K. Ingress protection requirements

These are some generic factors to be considered when selecting an industrial camera and lenses. Prioritizing the above factors makes it easier to select the best for the budget. Some industrial camera manufacturers even provide online tools for selecting best fitted camera for our problem by knowing the above factors.

For prototyping I would suggest using a cheap industrial/CCTV camera with a common lens mounting option, with around 5 megapixels CMOS sensor and supporting at least FHD video transmission.

Thanks I have some doubts. So based on your factors , I have some numbers, can you recommend any Camera brand or model?

A FOV (60-65 deg)

B. Distance (40-50m)

C. Sensor resolution: accuracy in calculation / 10cm error by 40m. So it should be in cm

D. D. Lighting conditions: (Auto exposure )

E. Communication interface: not important ant the moment, bandwidth sufficient for angle and obstacle detection

F. Lens for 60-65 deg FOV

I. FPS. Minimum 30FPS and Minimum HD resolution is 1280*720

J. according to application

K. according to application

Not for prototyping and not a cheap industrial/CCTV camera. Actually camera for this real system application

Thanks

I have good experiences with Point Grey / FLIR cameras. Have a look here for the selection: https://www.ptgrey.com/Camera-selector