Vertiq 8108: Braking, not Breaking

Vertiq is getting ready to begin its production run of the Vertiq 8108. To release the highest performance module to our backers, Vertiq has performed several tests to evaluate the motor’s ability to go from high speeds to 0 RPM under different conditions.

Vertiq first ran the braking test above on the Vertiq 8108 beta prototype with a T-motor 30x10.5 CF prop to measure its ability to reverse quickly and brake instantly. Quadcopters change their orientation by varying the speed of their motors, which controls the roll, pitch, and yaw of the vehicle. If the motors and propellers are able to change speed quickly, then the drone will be able to stabilize and change directions faster.

The test ran from 1,700 RPM to 0 with a rise-time (or fall-time) of 0.18 seconds, resulting in a speed rate change of 7,472 RPM/s. “Rise-time” is commonly used to describe the time it takes for a motor to go from one speed to another, but the term implies that the RPM is increasing. Specifically, rise-time is defined as going from 10% of the desired change in speed to 90% of the desired change in speed. For brake tests, we use the term “fall-time” because the speed is decreasing. Fall-time is conversely defined as going from 90% of the desired change in speed to 10% of the desired change in speed. In this case, the Vertiq 8108 went from 1,530 RPM to 170 RPM in 0.18 seconds.

The ability to stop or reverse speeds quickly is vital for highly maneuverable drones. It’s also important for unique operating modes, like deploying a ballistic parachute.

Vertiq also ran the obstacle test above on the Vertiq 8108 beta prototype to measure the current limiter capacity. Vertiq's firmware monitors the current consumption of output drivers and senses a spike in current when the propeller is met with an obstacle, such as a towel. It then triggers the preset current limiter to ensure the motor does not damage itself by continuously drawing current and overheating. The Vertiq 8108 engages the appropriate safety procedures when entering a fail state. For instance, if a propeller gets caught on the branch of a tree, the firmware will protect the motor from overheating, which in turn could save the drone from catching fire.

By showcasing these tests, Vertiq hopes to demonstrate its commitment to making vehicles safer and more agile.