Ball Collector Robot Design it is PDF file with step-by-step building instructions
To find out what parts you need to build the robot, go to the attachments.

What is the Ball Collector competition

It's one of the events/categories in the Arab Robotics and Artificial Intelligence (AI) Championship / Arab Robotics & AI Association robotics tournaments.
The Peninsula Newspaper

Schools / student teams participate. Teams build robots whose job is to collect balls and deposit them in a specific place (often a designated “goal” or area) within a set time. The goal is to collect as many as possible, or maximize points earned by how many balls are collected and possibly where/when they are deposited.

There are different categories (e.g. beginner and advanced) depending on age, technical level, or school grade