Introduction When faced with the task of designing and building a VEX robot, students (and teachers) will often immediately want to pick up their tools and materials and start building.  This may be the most active and fun way to get started, but it is not the best path.  Imagine introducing the sport of football to a group of students for the very first time.  Naturally, the tendency would be to start throwing the ball around right away, but this would not be the best approach. To truly master the game, there are a series of steps to take before beginning the actual play. Learning the rules of the game. What are the objectives? What actions are allowed? What actions are prohibited? Analyzing potential strategies. Stretching to get into optimal shape. Practice. These steps are all crucial elements to ensure success. Building a robot to play a competitive game is no different. There are a series of steps that make up the design process that are integral to ensuring the success of the robots, while giving plenty of opportunities for students to learn and develop crucial analytical skills. 

Strategic Design Strategic Design is the process of determining what a robot should be able to do. In this process you are not trying to solve the problems of what the robot will look like, or how the robot will complete its tasks. Strategic Design occurs before both of those problems can and will be solved. It is impossible to build a successful competition robot without knowing what the robot is supposed to accomplish. It would be like going for a walk without knowing the final destination. Any attempt to build a competition robot without having done the Strategic Design would still result in a robot, but the chances of it succeeding would be very low. 

Defining Objectives Designing and building competition robots is a rewarding and fun task. However, the task becomes much more enjoyable when done successfully.  How do we define success?” In terms of competition robotics, a successful robot is defined as one that can regularly win matches based on its own merits and skills. Throughout the design process, this needs to be the overriding goal. When making any sort of decision or trade off, the team needs to ask themselves, “Will this choice help the team win matches?” If the answer is “no”, then the decision needs to be revisited. Of course, this is a very broad question. There are also other secondary objectives involved, which may not directly (or even indirectly) lead to the winning of matches. Considerations such as aesthetics, design elegance and even “shock value” are all potential aims. However, objectives must always remain secondary to prevent them from interfering with the goals of success.

Analyzing the Game The overall goal in competition robotics is to win matches. When presented with a competition robotics game challenge, the first step is to analyze the game and determine the optimal way to win matches. Determining this optimal strategic design will allow a team then make the optimal physical design of the robot. The first step in analyzing the game is very simple – READING THE GAME RULES.  The game rules are the design specifications for a competition robot. The rules explain the objectives of the game, what actions are permitted, and which actions are prohibited. Almost all competition robotics games are structured so that a team wins matches by outscoring their opponents. Assuming that the game being played is in this format, after completely reading the rules a team needs to ask the following questions. 1. What are the different ways of scoring points? Make a list of all potential ways to score points, no matter how obscure they may be. Competition robotics games can often be much more complicated than a conventional sport. For example, in soccer you score points by kicking the ball into a goal. That’s it. However, in competition robotics there can be multiple ways to score points for performing an assortment of different tasks. In fact, sometimes these tasks are not fully obvious to the untrained eye. To avoid missing these scoring potentials, one must read every detail of the rules and also learn to read between the lines.

Cost Benefit Analysis The task that earns the most points may be incredibly difficult, while a task that earns less points may be very simple to accomplish.  It is for this reason that a cost- benefit analysis must be performed. In a cost-benefit analysis, a comparison between the cost of an item and the benefit of the item takes place. In the case of a cost-benefit analysis within the Strategic Design of a competition robot, the “cost” is the level of difficulty of the given task, while the “benefit” is the number of points earned or denied by the same task. The goal is to identify the tasks which give the highest ratio of benefit to cost.

How does one determine the difficulty of performing a task How does one determine the difficulty of performing a task? There are many factors to consider when assessing the difficulty of a task within a competition robotics game. Some of these include: How long does it take to complete the task? The more time spent, the more difficult the task. How much distance needs to be traveled to complete the task? This is similar to the previous item, since distance is proportional to time Many tasks within competition robotics require lifting and placing objects, thus the weight of the object is a factor. Lifting a ping pong ball is not as difficult as lifting a bowling ball. The heavier the object, the more difficult the task. Similar to weight is the height of the where the object is being placed. The higher the placement height, the more difficult the task. The precision required for the task. For example, parking a robot in a 12”x12” space compared to parking a robot in a 24”x24” space. The more precision required, the harder the task. Does the task require a specific mechanism to complete? Tasks that can be done in conjunction with other tasks involve less difficulty, since you can essentially do two tasks at once (or two tasks with the same robot feature.)  

Prioritization of Tasks Now that a cost-benefit analysis of all the potential game tasks as been determined, it is time to make design priority lists. To do this, start with two separate lists. The first list covers robot qualities. This is the list of “What should the robot be like?” Examples of qualities include: Speed - “The robot should be fast.” Power – “The robot should be strong, able to push things easily.” Agility – “The robot should be easily maneuverable.” Low Center of Gravity – “The robot shouldn’t tip over easily.” The qualities are based off the list of optimal tasks. The most desired qualities are the ones which are most critical to the success of the most optimal tasks. For example, if the most optimal task is placing baseballs in a goal on the opposite side of the field, speed would be very desirable in order to reduce the time spent traversing the distance across the field.