NASA JPL Martian Helicopter Aerial Manipulation Project
The goal of this manipulation project is to demonstrate that there can be a helicopter in the future capable of picking up and depositing a big sensor pod on steep Martian slopes. Most work here is done in the Center for Autonomous Systems and Technologies (CAST) of California Institute of Technology. Special thanks to Professor Joel Burdick and Skylar Wei for their help and guidance along the way.
How It Started…
We use two linear actuators in the middle to drive the arm – extending and contracting.
Below is the first version of the gripper. All custom made with CNC Carbon Fiber Pieces and the gears are printed with Markforged printer with special Carbon Fiber filaments.
Revision…
We added telescope tubes in the middle to help with the wiggling (latitudinal motion) and added plates to better position the Actuonixs.
How It Looks Now…
Load Cell Sub-Project
Using 6 load cells, we want to simulate steady-state hovering conditions for the drone using a fixed testing apparatus. There are three main things we are looking to get out of it:
Identify the relationship between the system center of gravity as a function of linear actuator positions.
Test and evaluate the anchoring sequence as the test apparatus tilt (ie. pitch/yaw).
Quantify the vibration induced by manipulation with the onboard accelerometer data.
Pictures down below feature the process of setting up and calibrating the load cell with Arduino. Note that this is still a continuing project. To be updated.
Drone in the CAST Testing Arena, ready for first flight after successful calibration!
Close-up of a fully tethered drone for safety purposes for initial testings
Reverse engineering a purchased carbon fiber piece so we can make more changes as we see fit.
When we realized we forgot to design 8 holes when manufacturing the center carbon fiber plate, instead of CNCing another one, we decided to modify the current plate. (Continued on next slide)
To ensure the holes are in the right position, we have to match the exact position. We decided to print out 1:1 ratio design and glue it onto the plate. As you can see in this picture, I marked out some holes' X and Y's axis. After matching the first two holes we just clamp/glue down the plate for the CNC to do the rest. It was proven a successful mission!
This was the final design with structures only (no props, no computer, no landing gear) and we were pleasantly surprised it only weighed 3.3 kg.
Close up of load cell calibration set up! Basically I would take an object, weigh it on the scale and the load cell and record the outputs accordingly. After tens and hundreds of trials then can we determine a rather appropriate/accurate slope and intersection for the load cell.
This is a 3D printed piece for landing gear attachment. It attaches the landing gears with thru-holes, and then it clamps on the arms with aluminum clamps as seen.