I have made four walking robots so far, but models with aluminum profiles and acrylic are too heavy to walk well on the ground. Since the weight of the robot is the most important factor, it was necessary to make the skeleton and the body excluding the motor and the battery as the lightweight material and the light weight design.
The acrylic body was changed to the foamex body, and the acrylic legs were changed to bamboo stick legs. The biggest advantage of this model is that it led to very successful results in light weight. The problem, however, is that when four legs of a robot are configured, the phases of a pair of left legs and a pair of right legs have to be exactly 180 degrees out of phase, but their respective leg positions are random.
To solve this problem, I came up with various methods. The first was to use Cds illumination sensor to automatically adjust the phase of the bridge software automatically. The second was to connect the accelerometer wirelessly to find out the slope of the x and y axis of the leg and calibrate it on its own.
However, both methods are not only hardware complicated, but also a clean alternative to software. So I wanted to change the structure of the legs so that the gears would mesh with each other to solve the hardware problem. With gears, the phase difference can be precisely controlled.
If I build a large model, the weight may cause the robot not to work. So, I tried to test it with a small model. I did not use an existing gear, but directly cut the gear with a laser cutter. The reason is that the use of metal gears rather than plastic gears in the existing gears is better than the existing gears, but since the holes in the gears have to be connected to the gears, the problems with the existing gears have not been solved.
I used two worm-geared DC motors (JGY-370), and the operating voltage is 12V to 25RPM. Rated output is 13kg * cm torque, maximum torque is 25kg * cm. The dimensions of the body are 70mm in width, 220mm in length, and 38mm in height.
Currently, I am assembling robots, but the most important thing when assembling is that I have to balance the bolts and nuts of the joints carefully and carefully. Otherwise, the bolt and nut fastening area of the joint can be released while walking. This work requires a high degree of tranquility and delicacy.
At present, the most problematic thing is that the laser cutter is defective, then the laser does not cut the acrylic vertically and cuts it with a diagonal line, so that the acrylic plates that make up the body are not perfectly coupled to each other. The balance is in a slightly collapsed state. Therefore, there is a load on the acrylic and the top acrylic is cracked.
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