Bipedal walking robot, need building advice

Community General Discussions
1

Hi guys,
I am building a bipedal walking robot that kind of look like this
starwars_paper-280x300.jpg
I am running into two main problems, one mechanical and one electrical

  1. How does a two legged robot make a turn?
    I think that to walk you will need two extra motors to shift the weight from foot to foot before making a step
    Two ideas so far on turning
    a) Have a motor to turn the entire leg as it is taking a step, and the other leg along with the body follows
    I have seen this form on other robots before, but I don’t like it much. It adds extra weight (which is already a concern), need extra space and is slow
    b) Just have one leg walk faster (take bigger steps) than the other
    The turning radius will be ■■■■ but I prefer to do it this way. But will this way even work?
    Any other ideas?

  2. To balance the robot and do some form of fall prevention do I just need a gyroscope or do I need a gyroscope and accelerometer?
    I don’t need to know how fast I am going, but I want to make sure the body is always leveled.
    If I do need a gyroscope what sensitivity should I use?

2

  1. Another way to make a biped robot turn is to spread the legs forward/back like walking and when both legs are on the surface, close the legs at the same time. Depending on which leg is forward, the robot will turn in one direction or another. This is how the BRAT Biped does its turns. This however requires that the feet of the robot drag on the walking surface, so there can’t be too much traction.

  2. You will need accelerometers in addition to gyros because the gyros will drift by themselves and the robot will think it is falling over even if it isn’t moving. We would recommend a IMU such as this one which has configurable sensitivity of both its accelerometers and gyros.

Also, as a reference point, there is the Lynxmotion Scout Biped that has a similar leg configuration to the one in your picture.