Different species all have different means of travel. That is to provide mobility in their surrounding environments. There are species that are bipedal, quadrupedal, and more. In this discussion, we focus on the mobility of quadrupeds. Animals vary in size, structure, and composition based on their adaptation to their respective environments. For example, cats are more very light, nimble, and flexible species, allowing them the leap great heights and distance when hunting for prey. However, bears are heavier, huskier, and agile animals for taking down larger prey, such as elk. We’ll be looking into how quadrupeds, specifically bear, walk.

The limbs of the bear can be looked at as two sets, the forelimbs, and the hindlimbs. Forelimbs and hindlimbs have different functions based on species of animals. Bears normally use their forelimbs to support about 54% to 60% of their body weight when walking on all four limbs. The 60 to 40 ratio is actually pretty common for quadrupeds, most likely due to the fact of added mass of the head at the front of the body. (Lee et al., 2004) In comparison, animals that use their forelimbs to manipulate objects and tools will support more of their body weight using their hind legs. For this reason, bears shift how they support their body weight depending on the action they are performing.

The feet of animals also vary in shape, size, and composition. Bird feet are very slender and have strong muscles to be able to perch themselves up or latch onto their prey. Horses have hooves to protect the padding in their feet to aid traveling long distances. Other mammals, such as bears, have padding at the bottom of their feet to protect all the smaller bones located in their feed. The padding also relieves pressure at the bottom of the feet for comfortable travel. Furthermore, the pads also assist the surfaces that bear walk on to avoid slippage. (Pataky et al. 2012)

When considering the purpose of each limb and padding of feet, we can determine a course of action for teaching our robot to walk. In our case, the center of weight for our robot is greater at the center. The weight of the head does not much make much of a difference in terms of using the forelimbs for more support. However, more calculations will be performed when considering the weight of the entire robot when the fuzzy skin surrounds the bear skeleton. Furthermore, adding grip to the bottom of our robot will aid in allowing the robot to push off on the surface it is traveling on. We found that having no grip would keep the robot in place because there is not enough friction to provide forward motion.

Further study and tests are needed to simulate the best form of locomotion for FuzzyBear. In order to aid with the walking of the bear, we will be using a servo shield that uses the CD4017 chip along with the MicroFOBO Poser application. The Poser application generates a table of the orientation of each servo for each frame. Combing of the frames will demonstrate a walking motion to allow FuzzyBear to walk.