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As detailed in Section 2.2, the primary challenge that our team will face in the development of this mechanism is balancing the forces required to achieve high output distances with the structural and positional requirements needed to enable repeated The biggest technical hurdle that must be overcome to reach the above objective is creating a mechanism that produces a large force multiplier effect while maintaining the structural integrity required for repeated, autonomous jumps. Our project scope is defined with this driving factor in mind:

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constrained to focus on this particular challenge by limiting other, compounding challenges:

• We will limit our mechanism to one DOF (vertical) to simplify the requirements of defining a successful jump. This will be achieved by using a superstructure anchored by guide rails rail system that will further ground our jumper mechanism.
• To enable quick position reset, the The mechanism will be designed to return to a singular base state after every jump to enable quick position reset. The mechanism superstructure and quick operational behavior will work in tandem to enable such a state.
• To lessen the forces required to induce a successful jump, the The sliding jumper in our mechanism will be designed to house as few electrical and hardware components as possible . Ideally, we will be able to solely house our driving to minimize weight. We plan to house only a DC motor and linkages within the jumper structure, with all necessary electrical and power input coming in from a fixed electronics box on the superstructure via lengthy wire connections. This goal will be adjusted based on what we find is practically possible during our design processother required electronics held outside of the system.

4.1 Initial Design Concepts

We will start our design process by developing a series of mechanism develop various mechanism design concepts that utilize unique kinematic approaches to achieve the goals defined in Section 2 and our stated operational scope of 1 DOF in the translational vertical direction. Given our goal of achieving high jumping distance, we will emphasize conducting robust motion analysis on our linkage designs through computational methods in order to optimize link lengths and behaviors. As we work to flesh these designs out as physical mechanical concepts in CAD, special attention will be paid to the mechanical properties of the mechanism—primarily the We will test these design concepts in CAD by conducting force and acceleration analyses on our design concepts using FEA to improve each design and rule out designs that are insufficient. We will focus most closely on the load-bearing “foot” link and the spring-loading link—to ensure their strength and robustness. We will do this using force analysis via hand calculations and FEA simulations. link aspects of the mechanism design due to their importance in achieving the high force and acceleration required.

4.2 Prototyping and Fabrication

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4.2.1 Developing the Sub-Components

After finding a winning mechanism design concept using FEA, we will enter the fabrication phase. We plan to iterate often, so we will initially create semi-functional prototypes to test specific sub-assemblies. We will make sub-component prototypes only out of materials and processes that we can quickly iterate on; laser-cut acrylic or wood, structurally optimized 3D-printed elements , and off-the-shelf components such as linear bushings. For example, we will build, test and iterate on only the CAM-DC motor link until it is sufficiently powerful and strong. We will do this with every sub-component before creating the full assembly.

We will initially create non-functional prototypes, moving to functional prototypes after ensuring desired and predictable motion output. We will evaluate the success of each design by measuring actual forces and distances that the device produces and overall robustness in operation. Material choices will likely change through both the initial design process and prototyping stage, as will link lengths and geometries. 

The most potentially-gating part of our project will be the superstructure and its components—with our implementation of vertical guide rails, we may need to introduce metal components into our design to support our mechanism and counter any moments that it may generate in order to maintain a 1 DOF condition. This may require machining, with a remote chance of us looking at potential production lead times depending on the complexity of our designs. Machined components may also be necessary for load-bearing components in our linkage system depending on the results of our structural analysis.

4.2.

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2 Critical Technical Milestones

When we are satisfied with each component and sub-assembly, we will assemble them into a full mechanism. We will continue to make modifications at this stage, but they will be modifications to sub-assemblies rather than full design iterations. 

We will continue iterating on the mechanism assembly until the following 2 critical technical milestones are reached:

• Milestone #1: Reproducibly achieve a vertical jump height of at least 2 feet.
• Milestone #2: Complete at least 3 autonomous jump and land cycles without failure.

5. Preliminary Design

The linkage mechanism shown in Figure 5.0.1 depicts both its jumping and loading state. The mechanism centers around a cam device driven by a DC motor (link 8), which drives a torsion spring (connected by links 4 and 2). The stretched torsion spring stores energy, and due to the legs compressing (links 1 through 4), the angle between link 6 and 1 compresses. Once the cam passes the torsion spring, it snaps back to its original jumping state and triggers the jump. Link 7 is the output link and will be attached to the mounting plate of the rail system, which serves as ground. Note that more torsion springs can be added at other joints to increase the stored energy for better jump height. There are two half-joints in this linkage: the contact between the cam and spring and the contact between link 1 and ground. The mechanism is intended to stay Grashof, with link lengths to be determined through iterative computational methods due to the complexity of the system. The mechanism is also intended to have 1 DOF , confirmed with according to the Gruebler equation below:

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