Schlagwort: Tracked Robot

  • Bendy robotic tank steers by flexing

    Bendy robotic tank steers by flexing

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    James Bruton has become something of a YouTube sensation by experimenting with unusual drive mechanisms for his robots. While he does do other things, most of his projects seem to focus on designing, building, and evaluating drive types that are far outside of the norm. His newest project is no different. It is a single-track tank vehicle that steers itself by bending its entire body.

    Bruton got this idea after looking at the way conveyor belts work. Those belts, which tend to be a series of interconnected segments, are obviously flexible along their length, which is necessary for them to bend and loop back around. But they are also slightly flexible in the direction perpendicular to that, which is necessary for the conveyor belt to make a turn. Bruton figured that if he could make a tank track bend in a similar way, he could make the vehicle turn without the need for a second track.

    To test this idea, Burton 3D-printed almost the entirety of the vehicle. That includes the track itself, which is made of several rigid segments that link together. There is just enough movement in the connections to allow a segment to sit at an angle relative to its neighbors. Conventional motors in front and back units spin the track, and an Arduino Mega 2560 board controls them. Between the two units is a joint that pivots horizontally. A linear actuator arm controls the angle between the front and back units, forcing the track to bend.

    While the turning radius is massive, this vehicle can maneuver. It isn’t very good at clearing obstacles, but that is more due to Bruton’s design than the drive and steering system. That could be improved with additional design iterations, but this vehicle already proves that the concept works.

    [youtube https://www.youtube.com/watch?v=E_keOPL12FQ?feature=oembed&w=500&h=281]

    The post Bendy robotic tank steers by flexing appeared first on Arduino Blog.

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  • James Bruton improves his triangle-tracked tank

    James Bruton improves his triangle-tracked tank

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    Tanks are already quite maneuverable, because the tracks allow them to rotate in place. But what if they were even more maneuverable and could drive in any direction? About a year ago, James Bruton built a small robot tank that had that capability thanks to a triangle-shaped track system with omniwheel-style rollers. But it had trouble climbing over obstacles, so Bruton redesigned his omnidirectional Triangle Tank in his newest video.

    The overall concept is the same as the original: three tank tracks arranged in a triangle formation contain rollers perpendicular to the track direction. The rollers let the tracks slide freely side-to-side, but provide grip when the track moves forward or backward. With three of those tracks, the robot can move in any direction by vectoring the relative rotational speeds. The original design struggled, because it couldn’t get traction unless it was flat on the ground. The new design has three differences to address that: trapezoidal tracks, a sort of pivoting suspension system, and dual rollers positioned on the outsides of the tracks.

    Bruton 3D-printed all of the parts, with the exception of the hardware and electronic components. Those components include an Arduino Mega 2560 board, an OrangeRX DSM radio receiver, and a trio of motor drivers. Power comes from a hobby LiPo battery pack and Bruton can use his custom DSM radio transmitter for control.

    The new Triangle Tank proved to be much more capable than the first version. While it isn’t quite as adept as a regular tank, it is far more maneuverable and does a pretty good job of clearing obstacles.

    The post James Bruton improves his triangle-tracked tank appeared first on Arduino Blog.

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  • Can a triangle of tank tracks outperform omni wheels?

    Can a triangle of tank tracks outperform omni wheels?

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    Arduino Team — March 16th, 2022

    Omni wheels are fantastic because they let a vehicle drive forward, backward, left, right, and rotate — all without a steering mechanism. There are only two catches: all four omni wheels must be driven and omni wheels don’t handle rough terrain or obstacles well. Tank tracks are perfect for rough terrain, so James Bruton thought to combine the two concepts. To test this idea, he built an Arduino-controlled robot with a triangle of tank tracks.

    This robot has three tank tracks, each of which is driven by a simple geared DC motor. Burton arranged those in a triangle formation, so each track is at a 60 degree angle to the other two tracks. Normally, an arrangement like this would be a disaster, as it couldn’t drive in any direction without dragging at least one of the tracks. But Bruton lined all of the tracks with small wheels, which have axes of rotation perpendicular to the track motor axles. Those wheels rotate freely, so the vehicle can move without resistance — even when that movement is perpendicular to one of the tracks.

    Movement requires the coordination of all three track motors in order to vector the motor speed. Bruton used an Arduino Mega 2560 board for the job, because it has plenty of pins available to control the motor drivers via PWM. It also had pins to spare for an SPI connection to an nRF24L01 radio transceiver, which receives commands from Bruton’s general purpose robot remote control.

    The robot drove quite well on smooth carpet and is able to maneuver in a manner similar to what you’d see with standard omni wheels. Unfortunately, it wasn’t able to handle obstacles. The tracks were too smooth to get traction on an obstacle and constructing them from a grippy material would have kept them from sliding when necessary. While the robot didn’t accomplish Bruton’s goal, it is still interesting to see in action and is a thoughtful exploration of alternative drive types. 

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