Intakes and grippers
Design capture geometry, compliance, retention, and jam recovery around the objects your robot handles.
An brings an object into controlled contact with the . A gripper retains it for manipulation. Both need to work with the object's actual shape, surface, orientation, and permitted handling conditions.
Capture area
Specify the object set and the range of lateral offsets, approach angles, and initial orientations the should tolerate. That range is the . If an intake only collects carefully placed objects, the driver must align the robot for every pickup.
Use guides, funnels, rollers, or shaped fingers to direct the object toward a repeatable retained position. Keep the path visible or provide reliable sensing.
Active and passive intakes
| Approach | Useful when | Watch for |
|---|---|---|
| Roller or belt intake | Objects need to be drawn through a capture path | Compression, rejection, entanglement, and jams |
| Actuated claw | The object needs a defined pose or controlled release | Driver alignment, closing geometry, and load on the |
| Passive fingers or scoop | Geometry can retain the object without continuous actuation | Approach , release, and impact forces |
For passive intakes and claws, compare complete acquisition and release behavior; part count alone does not choose the best mechanism.
Compliance
is controlled deformation under load. A flexible roller or finger can accommodate object variation, increase contact, and absorb impact. Excessive deformation can also reduce positional consistency or let the object escape.
Roller compression is the interference between the unloaded roller geometry and the object path. Too little may not provide useful traction; too much raises load, damages objects, or the mechanism. Tune spacing using adjustable mounts and representative objects.
Roller surface speed is . For an illustrative 50 mm roller at 500 , it is about 1.31 m/s. The object's actual speed will differ because contact slips and deforms. A higher roller speed can increase rejection if the downstream space cannot control the object.
Intake exit
Test where the object ends up, not only whether it crosses the intake opening. A wide capture area is useful, but the next mechanism may need a much smaller range of positions and orientations.
Use guides and continued contact to reduce that variation. Avoid launching an object across an unsupported gap into a narrow receiver. If the intake is also used for storage, check that a retained object cannot be pushed into a stalled roller when another object arrives.
Measure pickup and transfer separately, then run them together. A fast intake can overwhelm the next stage or produce inconsistent entry spin. The Transfers guide covers contact geometry, staging, and feed timing.
Retention and release
Check what happens when the robot brakes, turns, or raises the retained object. A grip that survives a stationary test may lose the object when changes the load direction.
For a simplified friction grip with two opposing contacts, each pressing with normal force , the available tangential force is roughly . This assumes stable friction and suitable contact geometry. Use it to see which quantities matter, then test the actual object; compliant materials and irregular surfaces rarely match a single fixed coefficient.
Release should produce a repeatable pose and path. Make room for fingers to open without colliding with a scoring target or the robot. A passive retention feature can reduce holding current, but it must still permit the intended release.
Jam recovery
Provide a way to reverse rollers, reopen a claw, or return to an acquisition position. Avoid a pocket that traps an object where no can reach it. Protect cables and fingers from rollers and pinch points.
Use a test grid with lateral offset on one axis and object angle on the other. Record captures, time, rejects, jams, and successful recoveries for each condition. Fix geometry that fails a whole region before trying to hide it with a longer .
Compare the distribution of acquisition times and driver corrections as well as the average. A few long jams can account for much of the time spent collecting.