TESA Technology is a Swiss division of Hexagon AB, a worldwide group leader in sensors, software, digital factory and digital world, as well as in autonomous solutions. In particular, TESA manufactures precision instruments for Hexagon’s Coordinate Measuring Machines (CMMs), notably probes and articulated motorised probe head for orientating these probes near the workpiece to be measured. Despite slotted brushless motors are cost-effective and efficient solutions for motorising devices, these motors produce, at slow rotational speeds, cogging torque that compromises its use in various measuring solutions.
This project targets the design of an anti-cogging driving unit of slotted brushless motors for articulated probe heads and probe’s rotatable joints. The project’s milestones comprise:
1) study of the technical background of slotted brushless motors, and definition of motor requirements for use in metrology
2) design and simulation of most-promising driving control unit
3) realisation of a functional prototype
4) validation and discussion of the realised functional prototype.
A large class of systems can be described by a linear but infinite dimensional systems. Example of such systems are LTI models with time delay, or systems governed by (linear) partial differential equations. The goal of this project is to implement a novel method to design continuous time controller, and validate it in simulation on two different systems.
Required courses: Advanced control systems
Required: MATLAB, some exposure to numerial optimization.
The Automatic control lab has recently acquired a new educational platform from Quanser: the Qube Servo-2.
The aim of this project is to first prototype a new set of “caps” that can be attached on top of the Qube, such that the dynamics are more challenging that a simple DC motor. This addition should be designed such that a large variety of dynamics can be obtained, by simply changing some weights.
In a second stage, identification and control of this system will be of interest. A gain-scheduled controller will be designed to stabilise the system, along with an estimator to estimate correct values for the scheduling vector.
Finally, the result will be compared to a robust controller, stabilising all different models simultaneously.
Required courses: System Identification, Advanced Control Systems.
Required knowledge: MATLAB, LabVIEW, some C programming
Mikron Automation is the leading partner for scalable and customized assembly systems.
The Polyfeed (https://www.mikron.com/automation-solutions/platforms-systems/feeding-systems/mikron-polyfeed/) is a feeding system able to feed components to be picked by a cartesian robot (X-Y-Z + rotation). The feed and pick processes are based on visual recognition and vertical vibration systems. The feeding speed can reach 80-110 parts/min, depending on the component design and size (varying from 1 to 50 mm3 size). The current trajectory implementation is based on a simple but optimized pick and place movement. A basic obstacle avoidance is implemented, based on delayed displacements across one axis.
Mikron is currently developing a Robotic Cell, which will have a layout similar to the Polyfeed, but will be used to realize more complex operations, as assembly or insertion of components. It therefore becomes strategical to introduce the notion of optimized path planning with obstacle avoidance, imposed waypoints and a target position. Given this information, entered by an operator on the user interface, the system must be able to propose the best trajectory, optimized with regards to speed and vibration aspects. It must also be able to recompute dynamically the trajectory in the case of an unexpected event.
The main activities for this project are:
(1) Familiarization with the existing trajectory algorithms and their implementation on the Polyfeed. (2) Study of existing path planning algorithms and selection of the most adapted ones. (3) Design and simulation. (4) Testing on a functional prototype. (5) Qualification of the trajectories based on measurements.