During Week 8, we applied changes to the design of the suspension.
In our original design, there was swinging due to linear acceleration and a lack of vibration damping on the vertical axis.
Figure 1. Original design
Our suspension design therefore needed to be modified to fit the design requirements. The addition of a linear actuator across the links allows for control of the links and a spring-damper system will damp the vibrations. The linear actuator will move in response to the position of the links and the acceleration of the pod car. The spring stiffness and damping coefficient will need to be calculated in the future to build the spring-damper system.
Figure 2. Prime design concept
FEA was also done on a CAD model of our system. Our results indicate that deflection is not a major problem and the minimum factor of safety is good for our purposes.
Figure 3. FEA on spring-damper support
In Week 9, we will refine our design even further and begin assembling a bill of materials.
Concept designing was discussed among the team members on each of our proposed ideas for the half-scale suspension. Colin and Joshua drafted up their designs using active suspension that would consist of some actuators and would involve an Arduino for control and some power source. Salvador drafted up his design using passive suspension that will be all mechanically driven by weight of the pod car to solve the leveling. After briefing Dr. Furman and Eric Hagstrom on the drafted designs they agreed that a passive system would be more ideal for the task of having the pod car remain level as it transverses on the inclines and declines of the rail as opposed to an active system for the sake of associated complexity and keeping component cost and energy low.
What the group examined carefully among the drafted designs is if they solve these basic problems:
1. The leveling of the pod car
2. The associated swinging that will arise with accelerations and decelerations of the pod car.
3. The u…
This week the team worked on developing our new concept to be incorporated into the half-scale suspension on SolidWorks. Our concept is to have the dampening system link not on the bottom like we originally had (Figure 1) but used as the center link to shorten the overall vertical length of the suspension (Figure 2).
After creating this CAD Model we got to see what are the limitations of our concept design based on the dimensions of our components and the overall form of the parts. We realized after measuring within Solidworks that we need improvement on getting a greater range of pitch angle because we are currently getting 19 degrees in incline and 24 degrees in decline. Also, further development of a modular design needs to be implemented in our design so that we can manufacture with easy and have the opportunity to reiterate the components without needing to cut away.
We will continue refining our CAD model and start to perform our analysis with FEA in the following weeks.