Installation¶
Warning
The instructions on Safety related to the rc_randomdot and rc_visard must be read and understood prior to installation.
Mounting¶
The rc_randomdot offers a mounting-point setup with standard tripod thread at the bottom, and pivot points for the provided mounting bracket on either side.
Fig. 9 Mounting bracket for connecting the rc_randomdot to the rc_visard
For troubleshooting purposes, the projector may be mounted using the standardized tripod thread (UNC 1/4”-20) at the bottom of the housing. For mounting the rc_randomdot on top of an rc_visard in static or low dynamic applications (e.g. above robot cells or on mobile platforms), the supplied mounting bracket must be attached to the rc_visard with two M4 x 10 8.8 machine screws, and the projector must be attached to the mounting bracket with two M4 x 10 8.8 machine screws at the pivot points. All screws must be tightened to 2.4 Nm and only TufLok nylon coated screws may be used. Alternatively screws need to be secured with a medium-strength threadlocking adhesive such as Loctite 243. Maximum thread depth is 6 mm. The supplied mounting bracket is not suitable for dynamic robot applications. It is the customer’s responsibility to provide adequate mounting of the rc_randomdot.
Warning
For permanent installations, the rc_randomdot must be mounted with four M4 x 10 8.8 machine screws tightened to 2.4 Nm torque. Screws must be Tuflok coated or secured with threadlocking adhesive. Do not use high-strength bolts.
Warning
The supplied mounting bracket is not suitable for dynamic robot applications. It is the customer’s responsibility to provide adequate mounting of the rc_randomdot.
Depending on the working distance, it might be necessary to tilt the projector downwards to cover the complete filed of view of the rc_visard. This can be accomplished by loosening the screws attaching the rc_randomdot to the mounting bracket at the pivot point, and moving the rc_randomdot to the desired angle.
Fig. 10 Setting the desired tilt angle between rc_randomdot and rc_visard
Power-up¶
Note
Always fully connect and tighten all M12 connectors on the both the rc_visard and rc_randomdot before turning on the power supply.
After connecting the system to power, the LEDs on the front of the rc_randomdot and rc_visard should immediately illuminate. During the rc_visard’s boot process, it’s LED will change color and will eventually turn green. This signals that all processes are up and running. The rc_randomdot’s status LED should turn green right away. The rc_randomdot projector will flash a number of times during the boot process.
Warning
Do not look into the lens of the rc_randomdot or into the light beam at any point during startup or operation.
For troubleshooting the rc_visard’s boot process and connections, please refer to the rc_visard documentation at https://doc.rc-visard.com/latest/en/troubleshooting.html#led-colors.
Operating the projector¶
The rc_randomdot projector is controlled via the GPIO Out 1 of the rc_visard. For a tutorial on operating the projector, please refer to: https://tutorials.roboception.de/rc_visard_general/projector.html.
Note
A valid IOControl license is required on the rc_visard. It is included in the standard on-board software package of all rc_visards purchased 07/2020 and thereafter. For upgrading an older rc_visard, please obtain your license at https://roboception.com/product/rc_reason-iocontrol.
State and behaviour of the rc_visard’s GPIOs can then be controlled via the rc_visard’s WebGUI IOControl panel from the Modules tab. Starting with rc_visard firmware 20.10, GPIO Out 1 is set to Low by default, turning the projector off. ExposureActive turns on the rc_randomdot for exactly the exposure time of every image. High will turn the projector on continuosly, but reduce power to 18% to protect the light source.
Typically, the user will select ExposureAlternateActive mode, in which the rc_randomdot is on only for the exposure time of every second image. Images with projected pattern are used for computing depth images. Images without pattern can be used for texture or other image processing modules.
In ExposureAlternateActive mode, the rc_visard’s auto exposure algorithm ensures that images with pattern are correctly exposed in order to produce dense disparity images. As identical exposure settings are used for the images without pattern, which are displayed in the WebGUI, those might be underexposed depending on overall illumination conditions. This effect can be minimized by properly adjusting environmental light conditions, projector lens aperture, and exposure time.
Adjusting focus and aperture settings¶
Remove the rc_randomdot’s protective lens cap by unscrewing it. To change focus and aperture settings, loosen the three small Phillips screws on the respective lens ring, turn the ring to the desired setting and lightly tighten the screws again.
For the location of the focus and aperture rings, please refer to Fig. 11.
Fig. 11 Focus and aperture rings on the rc_randomdot White
For focus adjustments, the projector should be turned on permanently by setting the rc_visard’s GPIO Out 1 mode to High in the WebGUI. For aperture adjustments, GPIO Out 1 should be set to ExposureAlternateActive and exposure mode should be set to Auto in the WebGUI Camera tab. Please refer to https://tutorials.roboception.de/rc_visard_general/projector.html for a tutorial on how to obtain dense depth images.
Starting from the largest aperture (smallest f-stop number on projector lens), reduce light output by decreasing the aperture until the white (high confidence) areas in the confidence image start to get smaller or darker. At the same time, the camera image should become less underexposed.
At this point, slightly open the aperture again to find a suitable compromise. Retighten the small Phillips screws on the focus and aperture rings to lock them in place and replace the protective lens cap to restore the IP54 rating and EMC compatibility of the projector.