The second project of the PM team? Venus Rover
The second project of the PM team? "Venus rover" . Authors of the project: Serdyuk Galina and Serdyuk Mikhail, Novosibirsk. The team participated in the All-Russian stage of the WRO of the past and the year before last in the main category.
“Since we are long-time readers of this journal, and have been interested in robotics for almost 2 years, and it is Lego robots, when we saw the announcement of the Russian Engineering Thought contest, of course, we immediately wanted to take part. Knowing that the theme of WRO this year will be "Space", we decided to make a robot that could solve any space problems. They began to collect information about various achievements and inventions made by Russian engineers who are related to space. We stopped on the task of moving around alien planets, at first we wanted to assemble a model of one of the Soviet moon rovers, for example, Luna-2, but in the process of searching for additional materials about it, we found a test video of the Venus Rover XM-VD-2, which seemed much more interesting. Because it has a non-standard form of wheels and unusual, effective means of transportation, ”say the authors of the project.
When creating autonomous transport robots, it is necessary to solve the problems of high cross-country ability on weak loose soils, driving on terrain with difficult terrain, timely detection of insurmountable obstacles and detours, providing energy for long-term work. Patency of a transport vehicle is largely dependent on the type of propulsion and the design of the chassis. This robot has a wheel mover. The chassis consists of 6 wheels with a developed supporting surface, occupying almost the entire width. All wheels are driven, with individual drive as a motor-wheel. The middle wheels are mounted on an articulated frame connected to the extreme wheels by longitudinal balancers. The extreme wheels are combined into bridges that can rotate relative to the longitudinal axis of the balancer. Turn is made by changing the speed of rotation of the wheels on the sides. With a different direction of rotation of the wheels along the sides, there is a turn in place. The robot is equipped with a wind power installation consisting of a rotary vane rotary engine, an electric generator for recharging the battery. The ability to move through loose soils in any direction largely determines cross-country ability.
The steepness of climb allowed for the Venus Rover can reach 44 degrees. As the angle of elevation increases, wheel slip also increases. The entire bearing surface of the wheels comes into contact with the ground, the track width increases, while the soil is transported by the hooks, the formation of soil shafts behind the wheels. The presence of individual stones in the ground makes it easier to overcome the ascent. The ability to move around a difficult terrain allows you to drastically reduce the number of maneuvers to avoid obstacles. This gives essentially a new quality when driving in autonomous control. Autonomous off-road transport robots can also be used for work in many remote and desert areas. And conduct their study for a long time.
I would like to realize in the model all the running capabilities that would be incorporated into the robot by VNIITM engineers. The hardest thing was to make wheels similar to the wheels of the Venus Rover. In the first version of the model, it was not possible to integrate the motors inside the wheels, so while all 6 motors that drive it are not located inside the wheels, they make up the longitudinal axis of the robot. Since a separate motor is required to bring each of the 6 wheels into motion, and one EV3 unit can only control 4 motors, 2 EV3 units are used in the model. In order for the motors connected to different blocks to work synchronously, a program has been developed with the help of which the blocks exchange messages wirelessly. The two remaining free ports of the block motors we used to control the drilling rig. One of the motors used in it lowers and raises the drill, and the second rotates it. Today's version of the robot is operated by the operator. An infrared sensor installed on one of the EV3 units receives signals from the EV3 remote control, the program processes them and transfers them to the corresponding movement commands for each of the motors connected to this unit and generates messages received by the second unit. For the robot, tests were conducted in which we examined its patency. The robot overcame a mountain of LEGO parts, imitating clusters of stones and loose soil with a slight slope, rode along a virgin snow and a snowy road, overcoming a steep descent. Tests have shown that due to the installation of leading motors for the robot, it led to an excessive weighting of the middle part and this worsened its running properties.
The first version collected for the competition is not yet final, it is planned to move the motors inside the wheels and realize the alternate movement of the axles. It is also planned to build a motor that allows the robot, if necessary, relying on two axes, to tear the third one off the ground, for example, to step it on an obstacle.