Overview
The objective of this initiative is to build a low cost open source robot that will pick up tennis balls on a tennis court. Often when players are practicing they tend to practice the serve from one side of the net usually 50 to 75 times in one go, once the basket of tennis balls is empty the player walks around and picks the tennis balls in the basket. This activity is not desired by many of the players for various reasons as this affects the player’s rhythm of practice or consumes additional time or the activity is difficult if the player is disabled.
Project Details
The main goal of this Project is to design a robot that will pick up tennis balls in a basket or hopper. At this point we have two different designs that have been proposed each with its own advantages and disadvantages.
The Player while practicing performs a few serves of the tennis balls and then instructs the robot to go around the court and pick up the balls. The robot will carry the basket around the court, senses the location of tennis balls using ultrasound sensors, once the ball is sensed the robot navigates to come close to the tennis ball and then activates the basket to lower it down using pneumatics to pick the ball, once the ball is picked the robot will sense for additional balls and if found any will continue on to pick those as well. Once a certain number of balls are collected in the bucket the robot will return back to the location from where it started.
Robot Design
Design Option 1:
Design a robot that will hold the “tennis ball pick up basket” that is available in any Sports Store and use it to collect the balls throughout the tennis court.
Mechanical Design - The robot should have a clearing on one side to easily collect the balls. The chassis of robot is kept low to provide balance and not tip over. The inside latches that hold the tennis ball bucket will also be on a guiding bar housed in the robot which can be moved up or down by pneumatic action, the downward movement to grab the ball and the upward movement once the ball is picked. Note, the actual picking action is mimicking how a human would pick the tennis ball using a tennis ball basket.
Electrical & Electronics Design - The robot will have the brains based on Arduino (or Raspberry Pi or similar board). There are two electrical motors attached to the two rear wheels to move the robot. The Pneumatic controls will move the tennis ball basket.
Sensors - The robot will carry ultrasonic sensor all-around (need to determine how many we need) to detect the tennis balls in the court. Sensors will also be used to figure out whether the tennis ball basket is full once the balls have been picked. We will also need sensors to detect and avoid any collision with anything that is bigger than a tennis ball.
Navigation - The robot will use sensors to navigate around the tennis court. We need to determine our choice of programming language to program the robot controls.
Design Option 2:
Design a robot that will pick up the balls using a feeder screw type mechanism into a ball hopper.
Mechanical Design - The robot should have a clearing on one side to easily collect the balls. The chassis of robot is kept low to provide balance and not tip over. The tennis balls are picked up from the ground using a feeder screw mechanism and pushed up the hopper.
Electrical & Electronics Design - The robot will have the brains based on Arduino (or Raspberry Pi or similar board). In this design more powerful motor is required to turn the feeder screw. The rear wheels are the driving wheels which are powered using motors.
Sensors - The robot will carry ultrasonic sensor all-around (need to determine how many we need) to detect the tennis balls in the court. Sensors will also be used to figure out whether the tennis ball basket is full once the balls have been picked. We will also need sensors to detect and avoid any collision with anything that is bigger than a tennis ball.
Navigation - The robot will use sensors to navigate around the tennis court. We need to determine our choice of programming language to program the robot controls.
Uses
There are numerous uses for this type of robot.
- A professional player would like to focus on his tennis serve while practicing and need not have to worry about picking and bringing the ball back, a robot will do.
- A disabled person can spend more time practicing rather than spending time on picking the ball (see figure 3.), also it may eliminate the need for a volunteer to assist the disabled to pick the ball.
- A tennis club which provides tennis coaching for beginners can use the robot for ball picking after the practice thereby spending quality time in instructing the players instead of picking the balls.
- Any player (see figures 1 & 2.) can use this robot, so that he can focus more on the game rather than spending time in picking up the ball afterwards.