This page provides information on how to purchase or assemble a Sensor Fusion Box. The Sensor Fusion Box is used in the CameraITS sensor_fusion test and multi-camera sync test. It provides a consistent test environment for measuring timestamp accuracy of camera and other sensors for Android phones. It consists of plastic box components that are laser cut from computer-aided design (CAD) drawings and a Servo Control Box.
You can purchase a Sensor Fusion Box or build your own.
Purchasing a Sensor Fusion Box
We recommend purchasing a Sensor Fusion Box from one of the following qualified vendors.
Rahi Systems Inc.
48303 Fremont Blvd, Fremont CA 94538, USA
4F., No. 163, Fu-Ying Road, XinZhuang District, New Taipei City, Taiwan
Building a Sensor Fusion Box
This section includes step-by-step instructions for assembling a Sensor Fusion Box from laser-cut acrylonitrile butadiene styrene (ABS) components (shown in Figure 1):
Figure 1. Mechanical drawing of Sensor Fusion Box components
Before starting, ensure you have downloaded the technical drawings for the Sensor Fusion Box (included in the Sensor Fusion Box zip file) and have the following tools available:
- Phillips head screwdriver
- Hex keys
- Power drill set
- Exacto knife
Step 1: Apply vinyl stickers
After creating the ABS components with a laser cutter, apply vinyl stickers to the plastic box to get the proper color control on the interior of the test box:
- Apply vinyl on the smooth side of the ABS as shown in Figure 2. For helpful tips on applying vinyl, refer to wikiHow.
Cut out the necessary holes on the vinyl with the exacto knife.
Figure 2. ABS pieces with vinyl applied on the smooth side (interior of the box)
Step 2: Prepare phone mount and attach servo mount
To prepare the phone mount to attach to the servo:
Tap 16 holes on the phone fixture with ¼" - 20 and make countersink holes on the back of the phone fixture.
Figure 3. Phone fixture with tap and countersink holes
With the large shaft that came with the servo, drill pilot holes with a #43 drill bit (2.26 mm) into the last holes from each side so 4-40 screws can be inserted through the holes.
Figure 4. Servo shaft with pilot holes at each end
Insert and tighten the flat-head 4-40 screws as shown in figure 5 on the front of the phone fixture and tighten the shaft as shown in figure 6.
Figure 5. Flat-head 4-40 screws
Figure 6. Shaft on the back of fixture, tightened by screws applied from the front
Step 3: Attach phone clamps
To attach the phone clamps:
Apply nylon thumb screws, rubber adhesive, and wire spring to the aluminum clamp.
Figure 7. Clamp with rubber adhesive, thumb screws and wire spring
Screw the phone clamps' thumb screws into the tapped holes of the phone fixture as shown in figure 8. You can adjust the location of the phone mounts depending on the size of the phones as shown in figure 9.
Figure 8. Mechanical drawing of clamp attachment to phone fixture
Phone mounts attachment to phone fixture:
Figure 9. Assembled phone fixture
Step 4: Assemble sliding door rail
Fix sliding panel rails on the top and bottom of the box towards the front. Figure 10 shows 6-32 screws on pre-tapped holes. Alternatively, you can use self-tapping screws.
Figure 10. Fixed sliding panel rail on top and bottom of box
Step 5: Attach lighting
To attach the light brackets and diffuser:
Stack two handle pieces on top of each other and assemble them using 6-32 screws (or use self-tapping screws).
Figure 11. Sensor fusion box handle pieces and assembly
Prepare four 4-40 screws, nuts, and acorn nuts to fix the mounting bracket from the lighting kit to the wall of the box.
Figure 12. 4-40 screws and light bracket on the interior wall of the box
Figure 13. Bolts and acorn bolts applied to the screws from the exterior of the box
Cut the light diffuser to an appropriate size to wrap the light strips.
Figure 14. Light strips and light diffusers
Wrap the light diffuser around the strip and tape it at the back.
Figure 15. Light strips and light diffusers taped from the back
Snap the lights into the brackets (can be a tight fit).
Figure 16. Lights not mounted in brackets (left). Lights mounted in brackets (right).
Step 6: Attach phone fixture to servo plate
To attach the phone fixture to the servo plate:
Prepare four 6-32 screws and a servo plate to fix the servo onto the wall. Fix the servo onto the interior wall and insert the screws from the inside into the servo plate on the exterior wall.
Figure 17. Servo and servo plate held in place with 6-32 screws
Secure phone fixture onto the servo with nylocks (pushing the center of the shaft into the servo's rotation center).
Figure 18. Phone mount fixed on servo shaft with nylocks
Screw the phone fixture onto the servo with its servo screw.
Figure 19. Securing phone fixture onto servo with servo screw
Step 7: Final assembly
To complete assembly of the Sensor Fusion Box:
Secure servo control box on the left of the servo with 4-40 screws from the outside and fasten from the inside with nuts.
Figure 20. Secure servo control box onto the wall
Tape the box together, then screw the parts together (you might need to pre-drill holes in some parts).
Assembled Sensor Fusion Box:
Figure 21. Taped box with motor assembly and servo control box and screw detail
Print out a colored copy of the checkerboard (included in the Sensor Fusion Box zip file) on A3 (or 11 x 17 inch) paper, and tape it on the opposite wall of the phone fixture.
Make sure the red dot in the center of the checkerboard is directly facing the camera when placed on the fixture, as shown below.
Figure 22. Checkerboard printed and taped to the opposite wall of phone fixture