Prototype Servo Design:
Figure 1: Side view of prototype servo design
Figure 2: Front view of prototype servo design
Figure 3: Top view of prototype servo design
Figure 4: Assembled view of prototype servo design
Final Servo Design:
Figure 5: Assembled view of final servo design
Figure 6: Isometric view of final part design
Attached to the servo on the side of the support arm, the purpose is for it to act as a physical brake to conserve energy. Because the servo is lightweight and has a great power output, the goal of this design is to achieve results with braking as accurate in stopping as power braking, with only a slight power variation from the coasting method of stopping (Refer to Coasting vs. Power Braking Testing and Servo Testing: Purpose and Methodology down below for more detail).
Servo Testing: Purpose and Methodology
The purpose of this experiment was to test the efficiency of a servo arm and motor as a method of braking compared to coasting the vehicle and power braking the vehicle.
The experiment was conducted in a similar manner as the Coasting vs Power Braking experiment, as the vehicle runs at a constant power for a set amount of time, then the method of braking is applied at the end.
The design of the servo arm was heavily inspired by the wheel design, as the part is intended to be an even fit to the track. The servo arm works by lowering the part to the surface of the track at a set time and cutting off power to the motors, it resists the motion of the vehicle and causes it to come to a complete stop.
Several configurations were applied, such as using rubber on the part to increase friction, therefore decrease stopping time. However, this proved to have safety concerns. With the rubber, the results came as expected and stopped sooner, but the braking was too sudden and would come close to falling off the track, especially at higher speeds.
The use of the servo without reinforcement about the arm was also applied. Experimentation proved that reinforcement was needed because the structure of the arm without reinforcement was not sturdy enough to hold on its own.
Servo Data:
Figure 7: Servo Braking Graph
Energy Consumption:
Trial 1: 13.950 J
Trial 2: 13.947 J
Trial 3: 13.962 J
Average: 13.953 J
Average Braking Distance: 0.1858 Meters