Students on the work-integrated Bachelor’s degree course in Mechatronics/Automation at the Gütersloh campus of Bielefeld University of Applied Sciences and Arts (HSBI) have developed a dartboard that moves into position so that a dart thrown at it hits the bullseye pretty much every time.

According to student Felix Lütkebohle, “Even the slightest wobble can throw a dart off-course, causing it to miss the bullseye.” But what if the board was able to move? A moving dartboard shifts within a split second to ensure the dart lands exactly in its center. All thanks to mechatronics design.

Over the course of seven semesters, students at HSBI learn to combine knowledge from mechanical engineering, electrical engineering, and computer science to develop sophisticated technical systems. This course's special feature is that it is work-integrated, with students alternating between academic terms at the university and work terms at a cooperating company where they are also employed. Felix is employed at Beckhoff Automation, and based in Verl, Germany.

Seamlessly Integrating Theory and Practice

“Integrating theory and practice is very important to us in both phases of the work-integrated study program,” explains Prof. Dr.-Ing. Thomas Freund, who teaches electrical engineering and automation in the Faculty of Engineering and Mathematics at HSBI. The most challenging project is the compulsory mechatronics project at the end of the course—which takes place during the last two semesters. 

The bullseye project was one of these. The project required various technologies, such as drive technology and image processing, to be combined and perfectly coordinated. It is only the subject matter of the bullseye project that makes it different from tasks with comparable requirements in an industry setting. “Our projects always revolve around simulating industrial working methods,” explains Thomas Freund. This includes working independently and as part of a team, using industrial components, and working through all stages of project management, from planning—including specifications, risk analysis, and time and budget planning—to execution, documentation, and acceptance measures such as CE markings and declarations of conformity.

The student team included Felix Lütkebohle, Louis-Pierre Detemble, Linus Bröker, and Jule Brede. Exception for Jule, who completed her work-integrated HSBI studies at Schüco International KG, all the students were also Beckhoff staff. The interplay between the different technologies built upon each other. For example, to implement proper image processing, the mechanics had to be in place first. Jule concentrated on that aspect, while Louis-Pierre and Linus took care of programming, and Felix was responsible for image processing and project management. The four students were the third team to work on the project. Their goal was to increase the hit rate and make the system faster. 

“According to the rules, the distance between the dartboard and the person throwing the dart must be 2.37 meters. From the time the dart is thrown, it takes only 140 to 150 milliseconds until it hits the target. That’s not much time to calculate the trajectory and position the dartboard accordingly,” Felix explains. The students focused on image processing and were able to use newly developed industrial cameras with a higher recording rate so that more images could be taken to calculate the trajectory.

Beckhoff provided mechatronic components to the project and greatly benefits from employees who have received outstanding training, according to Dr. Ursula Frank, who manages R&D collaborations at Beckhoff Automation. She adds, “We’re thrilled that we can use the findings from the study projects to optimize and further develop our own industrial solutions.”

For Felix, the introduction of new cameras with a higher recording rate meant reprogramming the image processing: For the project to work, the trajectory captured by the cameras in three dimensions must be displayed as a ballistic curve in order to calculate the exact position at which the dart hits the target. This must be achieved in half the flight time. In the remaining 70 milliseconds or so, the center of the dartboard must be driven to the calculated position. A high level of dynamics and precision is required from the linear motors installed. “The motors don’t rotate like conventional rotary motors, instead they push the objects being driven in a straight line,” explains Thomas Freund. While gravity helps with the dartboard’s downward movement, the team chose to install a second auxiliary drive to make the upward movement faster.

Although documentation isn’t the most fun part of the project when what’s really interesting is the technology, but the student found that it works best when documenting things as you’re doing them is the most efficient way. According to Jule, “If you leave everything until the end, you’ll end up getting mixed up or running out of time. Plus, the documentation will be extremely useful for the next team, because the bullseye project is still not finished after its third outing. Felix throws a dart. “There’s always room for improvement.”

The bullseye study project is underway thanks to the support of the following sponsors: akki Werbetechnik, Beckhoff Automation, Carbon-Werke Weißgerber, Dreckshage, Franke, Harting, igus, Mädler, Metallbau Helmut Blomberg, Rittal, Schüco

For information: 

Beckhoff

Beckhoff Training Offerings

HSBI