ModulArm
Whenever you want to do research in robotic manipulation, or want to test a control algorithm on an arm, you currently have to look at all of the different robotic arms on the market, and purchase one that most closely matches your application. What if an arm could be designed such that it is completely modular and reconfigurable? That's the reason Justin Kunimune and I developed ModulArm
There are currently four modules. The first is the base module, which is able to be bolted into an existing surface and allows for unlimited rotation around the z axis. Next is the elbow module, which allows 180 degrees of rotation. Third is the Twist module, which allows for unlimited rotation in axis with the arm. Finally is the end effector module, which we currently have configured as a claw gripper.
All of the modules can be configured in any order, using spring-pin connectors to create the electrical connections, and magnetic latches to rigidly connect between joints.
Claw
Each module has a built in micro controller, motor controller, and stepper motor. This allows for each module to be completely independent of other modules, and via I2C communication can be individually controlled. Below is the insides of the twist module, as an example of how tightly the joints were packed with electronics.
In order to achieve such compact design, we designed custom PCB's for the micro controller and the spring pin connectors using KiCAD. The current iteration is using a custom developed PCB that will contain the motor controller as well as an IMU sensor, so we can move away from stepper motors and use brushless DC motors with a much higher torque density to drive the segments. This will allow for much longer chains of segments to be linked before the torque limits are exceeded (unfortunately, only one or two segments can be used on the current arm before the stall torque is exceeded on the stepper motors).
