For some time I have been interested in creating my own walking robot. Not so much the two legged human like but more replacing wheels with something resembling a leg or leg type motion. I have sort of designed and made a four legged quadruped type spider thingy which was OK but was difficult to get walking, as in, I didn't get it to walk. I could never work out the gait. It is all to do with the centre of gravity as with a leg at each corner if you lift one leg the whole thing falls over. So you have to shift the centre of gravity to a more stable three legged point and then lift the fourth leg. Plus it needed two micro servos for each leg. For this type of spider type walking you either need six legs (which requires 12 servos) or three servos per leg (which also requires 12 servos). Once into the high number of servos region you then run into power supply problems, which I solved by using two battery pack, but this all makes it heavy, expensive and difficult.
I thought there must be a better way, so I have obtained an Elegoo Penguin robot. This has two servos per leg and uses big wide feet to solve the balancing problem, although it will still fall over. It does walk albeit quite slowly and really only on very smooth surfaces. See video below:
This is a possible approach and I think it has some good pointers. Particularly the use of big feet to help with the balancing problem. It maybe that if some sort of knee joint was added this might walk a bit better.
An alternative approach is provided by a toy called Tobbie which uses some sort of six legged spider motion. Interestingly all the batteries, controller and sensors are in the top half of the robot which enables it to rotate through 360 degrees without getting wires trapped inside. It does also make it top heavy and the centre of gravity is much higher but a wider spread of legs is used to overcome this. The video below shows the top half of the construction, with the long pin showing the movement provided to the bottom six legs, which is some sort of up/down rotation. It looks like it should be something that could be reproduced with some 3D printed parts such as cams and levers. Something to look more closely at I think. Apologies if you cannot hear the audio in the second half of this video but the Tobbie mechanism makes a great deal of noise and tends to drown out all the other audio.
Well, I'm off to finish making Tobbie and to think about how to make my own 3D printed walking mechanism/robot.
Dubbie
Top Comments
-
danielw
-
Cancel
-
Vote Up
+2
Vote Down
-
-
Sign in to reply
-
More
-
Cancel
Comment-
danielw
-
Cancel
-
Vote Up
+2
Vote Down
-
-
Sign in to reply
-
More
-
Cancel
Children