Drive train stattributes

Yeah so I am trying to figure out what 3 key mechanical attributes on a robots drive train are the most important for determining robot to robot interaction. My current list is (in no particular order)

  1. Speed
  2. Torque
  3. Acceleration

This thread is specifically about swerve drives but a lot of the content is relevant.

In my opinion, the most important attributes are robustness and maintainability.

Others, like traction, speed and torque are easy to adapt to a specific game by swapping COTS wheels and gearboxes, but the chassis (if custom), which primarily determines robustness and maintainability takes a lot of thought and design time to make.

You will find that those three attributes are linked to one another, and you will have to make tradeoffs to suit your preferred playing style. There is no right answer; it depends how you want to play the game. You should also consider directional maneuverability - being able to drive sideways can be advantageous at times.

While all things mentioned are important stats and attributes a lot of them aren’t exactly the data I am looking for. I wanted to graph the interaction between robots on the field in such a way where I could determine the appropriate emphasis on driving. Just playing on advantages and such. I’m really looking more towards getting information so I can quickly visualize how I need to tell the students to adapt driving based on match ups.

What about precision maneuvering?
This year I saw many robots that could fly around the field bashing other robots, but when it came to running down a ball and capturing it their effort was pathetic. Ball manipulation was key and I saw few teams that mastered it.

I specifically made them linked the graph I am doing is kinda based on the typical Real time strategy rock paper shotgun chart. Unfortunately I haven’t done one in forever and I am feeling rusty.

When you say “interaction” are you referring to collisions? Pushing matches? Races? The important mechanical attributes are different for each scenario.

The answer is highly game-dependant.

Speed is often important in games with long stretches of travel.
(In my experience, 2011, Logomotion was a good example of this.)

Acceleration is important for traveling short distances quickly.
(Example: 2012, Rebound Rumble with the field cut in half. A dedicated scoring team could easily stay within their key area the whole game with the right ball acquisition strategy.)

High torque is important for games which require precision movements of a drivetrain (most teams aimed with their drive base in 2012), also for defensive games like 2007, Rack N Roll, where avoiding defensive robots was nearly impossible.

I guess the answer is All of the Above? Having a drivetrain with all of the abilities you mentioned would be the optimal situation; however, it’s impossible to rank the qualities without knowing the game’s demands.

Some people often tend to say that a drivetrain that can push through anyone is the best option; but, i believe that time spent pushing a defender is time wasted, as it’s the defender’s job to keep your score down. Your best strategy as an offense is avoiding defense, not trying to plow through it (unless of course there’s blockading, which is totally illegal, but I’ve NEVER seen it called by a referee before).

Thats is more game dependent and rule specific but this is where the chart gets fun you take 3 core stats and you have a triangle fairly simple but you can add more complexity by adding more traits and then the shape rapidly grows out of control. Think big bang theory rock paper scissors lizard spock

This is reassuring cause it makes me feel not crazy. From year to year there are certain interactions robots on the field always need to do, this will (hopefully) never change. Things like zoning, peeling, and shoving matches, all these little skirmishes can change the flow of a game and I suppose I should start with a list of robot vs robot interactions and determine attributes from there.

Uhh going to go with yes. Despite the amount of scenarios your drivers style doesn’t need to be tailored too much to adapt to challenges.

This.

Traction.
Power.
Division of power.

Without traction, you’re not going to be able to push (or you are). Different wheels give different traction.

Power is how much power a drivetrain has available. See “motor count and type”.

Division of power is where the robot is on the speed/torque splits. High speed/low torque, vice-versa, shifting drivetrain… Get high traction and high power and mess up this one, and you’ll probably get pushed around at some point.

Robustness and maintainability are also important, but I’m assuming that all drivetrains are built with those included.

You’d be surprised.

It’s very easy to overlook maintainability when designing things, especially if you’re a high school student. I know that I sure struggled with it back when I was a student on 449.

I’m well aware that not all drivetrains are built that way. But for the sake of argument, I was making that assumption. You don’t operate in a frictionless vacuum when practicing physics, do you? Thought not.

In all fairness since my job is to optimize drivers to perform the best, collateral damage is a given. Sorry mechanical team I love you guys

Although it is game dependent, if I had to choose one of those qualities, it would be acceleration. If I had to rank them, it would be acceleration, then speed, then torque (although these are linked so it’s hard to distinguish because one affects the other).

Why? Because with acceleration, you can sprint and outmaneuver opponents very easily, and then if you have speed they can’t catch up. On the contrary, when you’re playing defense, you can stick to the opponent and don’t have to worry about getting juked because you can quickly accelerate back to them. The reason I de-emphasize pushing power so much is that in my experience, I have very rarely ever had to get in a shoving match forwards and backwards. The only pushing I’ve found to be effective (both doing it to other teams and having it done to my own) is friction pinning on the side of the robot, and it really doesn’t take a whole lot of torque to do that.

I’m sure you have all read this but the best resource on this subject is from Simbotics: http://www.simbotics.org/resources/mobility/drivetrain-selection
From the weighted objectives table:
Agility
Strength
Motors
Program
Drive ?
Traverse
Design

This is so true. We broke 8 axles at Portland one year by 10 AM Friday. They were putting the last of their spares when I called and suggested that they convert from 2 motor to one motor. No more broken axles that year and we still could push anyone we wanted to. When in low gear we had more torque then the axles could handle. We did not have reliability and that is needed far more.