Truck with adaptable air springs
This model is based on the off-road truck 8297, and it features adapting air suspension, which is controlled by two NXT bricks. the idea is that the two sensors in front measure the distance between them and the ground, and if the vehicle reaches a bump or a hole, the sensors measure a change in the default length, thus sending a signal to the NXT brick, which control the air springs (cylinders) and, consequently, soften, or increase the firmness of the shocks. The idea is to get a flat and comfortable ride, as the suspension would adapt itself to the terrain. OK, a bit about the construction.
The basis of this creation is the chassis of the off-road truck, as it possesses a fairly stiff and rigid suspension, so it would be a good place to start. Next, I got 12 lego pneumatic cylinders, which i adapted in the following way. Since I would need them to be able to expand and contract fast, I adapted the cylinders to be more responsive and to have less friction between the shaft and the cylinder body. Then, i put 4 cylinders in each of the corners of the suspension. The other 8 pneumatic cylinders i used to create the controlling blocks, which are crucial for the function of my model. the controlling block is made up of 2 cylinders, connected to a Motor, controlled by the NXT brick. the Motor expands or contracts the cylinders, which, consequently, blow air in or out from the cylinder in the suspension. the idea is to control the suspension using 4 of these control blocks, and since a NXT brick supports only 3 engines, i have a separate NXT brick for the left side and the right side. the cycle of the Program goes like this: if the Sensor in front of the wheel detects a change in the default length, it sends a signal to the computer, which controls the engines, that contract the two cylinders, attached to it, and suck air out or pump air into the cylinder of the suspension. The cool thing is that you can have a bump only on the left side, so only the left side will go through this cycle, while the other stays flat. on the main picture, the nxt motor that sits between the front and the rear tyre is part of such a controlling module. there are 4 such modules: one on each side, one at the back, and one on top. The rubber strings you see i used to strengthen the rigidity of my contraction, and to reduce the shacking of the sensors, as they would give wrong data, if shaken too violently. For the steering and driving, I put another NXT, as it would be quite hard to have two algorithms in one program. let me know if you like the concept in the comments below, what i could improve, what you like, what you do not like.