Landing Gear

The landing gear is a subsystem designed to assist testing or, more specifically, maintaining the bike upright when beginning and ending testing. The landing gear is controlled via a toggle switch (Channel 5) on the RC that deploys and retracts the wheels.

Schematic/Design

The landing gear is a DC motor (##) controlled by two relays (from the relay module) and powered by a standard 9V battery. The two relay's input signals (in3 and in4) is connected to the pins 47 and 48, respectively. As seen on the schematic, the relay's normally open (NO) and normally closed (NC) terminals are either connected to directly to the motor or to the COM of one of the limit switches. The best way to understand the schematic is by understanding what occurs when the relays are on NC or NO. Fundamentally, when the relays are on NC, the motor rotates in one direction. If on NO, the motor turns in the opposite direction. The limit switches are connected in the NC configuration, meaning that the circuit between the relay and the motor is normally closed until the limit switch is triggered. Hence, when one of the arms hits the limit switch, it opens the circuit and causes the motor to stop. Note that triggering one of the limit switches does not prevent the motor turning in the other direction.

Electronics

The landing gear system is an assembly of different electrical components, specifically a relay module, limit switches, and a DC motor.