The Design of Mechanical Walkers: Spring 2020 Student Projects

While isolated to slow infections of the Coronavirus, over 60 UCI students learned how to apply the principles of Curvature Theory and Finite-Position Synthesis to the design leg mechanisms for mechanical walkers.

Their first team project was a four-legged walker that used the coupler curve of a four-bar linkage positioned using a skew-pantograph as the foot trajectory. Here are videos that show animations of their walkers

This is the first video:

And this is the second:

The final team project used finite-position synthesis to design function generators to drive the hip and knee joints and guide the foot trajectory. This mechanism is a generalization of the Jansen leg mechanism. Teams of three students designed the leg mechanism, the drive system and assembled them into a six-legged walker. Here are the videos of these walkers.

This is the first video:

And this is the second video:

The variety of these walkers show the versatility of the kinematic synthesis procedures, as well as the creativity of the students. It was a pleasure working with the students on these projects even with the challenges of remote instruction.

Fall 2019 Mechanical Walker Prototypes

I was pleased to have an enthusiastic group of graduate students work with me on the design of four-legged walkers as the final project for MAE 245 Kinematic Synthesis. Each of the teams designed a four-bar linkage using Curvature Theory to obtain a coupler curve with a flat portion that could be used as the foot trajectories for the legs of the walker.

Then, they placed the coupler curve in position to form the feet of a walker by using a skew pantograph for the front legs and rectilinear six-bar linkages for the rear legs. I required this particular choice of the type of legs, simply because I was not sure which would work better.

This video shows the operation of their design prototypes. They all work as designed, though we have more work to do on their fabrication in order to improve performance.

Four-legged Mechanical Walkers: Teams 2, 4 and 5

Here are videos of the designs for the four legged mechanical walkers obtained by Teams 2, 4 an 5. This is the final project in my Fall 2019 Kinematic Synthesis course.

Team 2

Mechanical Walker Team 2

Team 4

Mechanical Walker Team 4

Team 5

Mechanical Walker Team 5

Four Legged Mechanical Walker: Teams 1, 3 and 6

Here are videos of the designs for the four legged mechanical walkers obtained by Teams 1, 3 an 6. This is the final project in my Fall 2019 Kinematic Synthesis course.

Team 1

Mechanical Walker designed by Team 1.

Team 3

Mechanical Walker designed by Team 3

Team 6

Mechanical Walker designed by Team 6.

Halloween Display 2019

This video shows how the linkage systems moving spooky decorations designed by my six student teams were combined into a Halloween display.

More Halloween Linkage Designs

The Halloween decorations designed by project teams 4, 5 and 6 can be seen in the video

Halloween Design Project

Students in my MAE 245 Advanced Kinematic Synthesis class have designed Halloween decorations using a four-bar linkage by itself or in combination with a parallelogram or pantograph linkage. You can see the work of teams 1, 2 and 3 in the video:

Walker Group 6

Mechanical Walker Project Animations: Spring 2019

Here are the solid models of some of the walkers designed by UC Irvine students in my Spring 2019 course MAE 183 Kinematic Synthesis of Mechanisms.

Walker Group 1

Walker Group 2

Walker Group 4

Walker Group 6

Walker Group 8

Walker Group 9

Walker Group 10

Leg Mechanism for a Mechanical Walker

This is an animation of the leg mechanism for a mechanical walker designed using function generators to drive the hip and knee joints. A second parallelogram linkage is used to construct a translating leg that allows placement of the foot trajectory where ever the designer chooses.

Construction of a Leg Mechanism

This is a series of four videos that show how to:

  1. Specify three positions for the foot of a leg consisting of a hip and knee joint;
  2. Use three position synthesis to design a four-bar function generator to guide the hip joint;
  3. Then use three position synthesis to design a second four-bar function generator to guide the knee joint;
  4. And finally assemble the linkage to determine the trajectory of the foot. Adjusting the lengths of the leg segments, the position of the hip, the specified positions of the input cranks, and the position of the coupler attachments to the input cranks vary the resulting foot trajectory. An example leg mechanism is shown at the end of this video.

Part 1:4 Setting up the design

Part 2:4 Synthesis of the hip function generator.

Part 3:4 Synthesis of the knee function generator.

Part 4:4 Assembly of the leg mechanism, exploration of design variations, and an example final leg design.