I'm puzzling over the remake of an impact testing machine. It's a sort of a robot arm that pushes a probe against a target to test its characteristics.
Right now the machine use air pistons, because it's easier to decide the force to exert. The probe is a ball of about 0.5 kg and 8 cm in diameter.
The machine should control three main parameters:
speed at the moment of the impact (roughly between 100 mm/s and 20 m/s)
force to exert against the target (roughly between 5 N and 100 N)
duration of the holding after the impact (between 100 ms and 10+ s)
The goal is to try to redesign the machine using only electrical actuators, like steppers or other motors, avoiding the pneumatic systems.
I'm looking for some ideas how to design the mechanical device to fit the requirements.
Some idea that won't work:
using a standard linear actuator or a stepper coupled with an endless screw: you can easily control parameters 1 and 3, but 2 it's very hard to achieve
using a cam to accelerate and launch the probe without a hard-link to the mechanism: you cannot control the third parameter and hence neither the second