Two Legs are Better than One

by Ben

April 23, 2005

Michael was going to play baseball. He had a great ability to hit, and an extremely good eye for the ball. He knew he could hit home runs like nobodies business. He steps up to the plate, the pitch is thrown, *CRACK* it's a line drive to center field. Michael starts moving towards first base, but before he even gets 10 feet, he falls over. He yells out in pain, his leg feels broken. Michael didn't do anything too strenuous, He's just top heavy. He has a weight problem, and because of that, he can't move quickly and he has poor balance when he does try to. In addition, his lower body is not designed to carry the excess weight. That's why his leg snapped.

Now we can all feel sorry for Michael, but Michael doesn't exist. He was a human example of a danger that exists in the development of bipedal machines such as mobile suits. Modern human beings are in truth, an evolution (all you creationist, please bear with me) of a species that though is capable of bipedal movement, was originally designed as a biped/quadruped.  It is a known fact that quadruped is dramatically more stable and balanced than a biped, because instead of the entire weight of the body being directly down on two parallel points, the weight of the quadruped is evenly distributed to four points, with perhaps a little bit of pull distributed to the center. The same can be said of any creature with more than 4 legs. Now, moving into how this applies to our future in technology, is building a bipedal robot really a good idea? They will have the same fundamental balance issues humans have, with more gravity to handle and more wind resistance. So again I say, is a bipedal robot a good choice, or should mobile armor designs like the BuCUE be more the standard? There are a couple things to consider in this choice.

A bipedal robot has three key advantages over a quadruped: hands, rotation and familiarity. Hands or even manipulator claws allow a mobile suit to do something it otherwise couldn't, including using portable weaponry simply by retrieving it, pick up objects or people, and allows for retrieval missions without additional storage or equipment. In addition, hands allow you to punch. Hands are by far the most familiar part of the human body, and we would be quite hindered in our everyday actions without them. Hands also allow the use of traditional melee weapons, which could be extremely useful. A second major advantage of bipeds is rotation. While not a guaranteed factor, having waist rotation is an incredibly critical part of human design. With a waist that can rotate and move, and utilizing the balance of the bipedal suit, it is possible to defend, dodge and avoid attacks without physically moving the suit. A quadruped does not have this advantage, as since it is dependent of all 4 legs for balance, it must physically jump or sidestep to avoid being attacked. A third major advantage of a bipedal design is familiarity of use. No one will deny that having a pair of hands a pair of feet and a head makes it so you wouldn't have to second guess your perceptions. In a quadruped, there would be more of a learning curve on how to judge movement rates and what the quadruped is capable. This assumes that the biped has someone close to human ability in movement.

Now that's not to say that quadrupeds don't have their own advantages, but this is an article on bipeds. Now that we have outlined the major benefits of a bipedal robot, lets go back to poor broken legged Michael. Poor Michael broke his leg because he was too heavy up top, and probably stepped down funny. So how does this equate to mobile suit design? It is a lot more relevant that you think. In mechanics, there are no bones, muscle and skin that are flexible or supportive. Everything is rigid.  Because of this, a warped beam or a broken strut can severely hamper a mobile suit. There are no sprains or strains that heal over time and small damage can accumulate and become big damage. This is why you never see, or should never see a fat mobile suit. A top heavy suit puts heavy strain on the lower torso and extremities every time the suit takes a step. Not only does the suit have to compensate for the wear and tear of walking in general, which for a 10 meter robot is extremely high, but it also is taking additional strain from the weight bearing down on it. Try an experiment. Take a thin sheet of steel and place it on two separated blocks. Put a small rock on it. Now, most likely, the steel will flex a tiny bit or bend, and the rock will just sit there in a crevice now. Now repeatedly slam the small rock into that steel sheet, the same each time. The steel will gradually start to become dented and warped, and eventually either snap or crease. These types of accumulated damage can occur in any type of walking robot, bipedal or otherwise, but in a biped if one leg becomes disabled, the suit becomes unable to move.

Now let's take a more serious issue, vernier/rocket flight in suits in an atmosphere. How many times has the Strike Gundam jumped off the Archangel and just landed 2-300 feet below and jump into combat? Now given, I don't know the durability of Phase Shift armor, or gundanium, or lunar titanium, but if the suit was made of steel, well if you've ever seen a plane crash on footage, you know that high speed impacts can cause just as much damage to machinery as anything else. The truth is, this type of combat is extremely unrealistic due to the immense amount of damage that could be caused by landing at such speeds, even when decelerating with engines. A biped has even more chance to be caused damage because the entire weight of the suit follows it down, and immediately transfers the kinetic energy to the leg joins and struts of the suit. I'm surprised no one has ever just shattered the legs of their suit from that. It is for this reason that the upper body of a bipedal mobile suit MUST be lighter and thinner than the lower body, even putting durability of joints aside, a top heavy mobile suit will not be balanced. Without that, we can expect a lot of military hardware to be destroyed because it can't avoid attacks, defend well or shift its body. I wont even get into the dexterity issues.

The next season, after his leg healed up, Michael lost weight and tried out again. He actually made it to first base this time, but unfortunately, he caught a stray beam rifle blast and the rest is history.

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