Dennis Bruijnen

Realtime motion path generation using subtargets in a rapidly changing environment

In this work an algorithm is proposed for path planning in a rapidly changing environment. The algorithm is computationally cheap and generates a sub-optimal smooth path with bounds on the allowed velocity, acceleration, and jerk. The algorithm is designed for holonomic omniwheel platforms. It outperforms potential field algorithms regarding both convergence and optimality. Furthermore, it is able to adapt fast in a rapidly changing environment due to the low computational cost in the order of ms for a single update, in contrast with computationally more expensive methods such as wavefront algorithms and global optimization methods, where the computational cost is mostly on the order of seconds. The algorithm will be tested via simulations and experiments.

Optimization aided loop shaping for motion systems

An approach is proposed which improves the quality and speed of manual loop shaping. Loop shaping is an iterative and creative controller design procedure where the control engineer uses frequency response function (FRF) data of the plant to shape the open loop response such that it satisfies stability, performance and robustness specifications. The advantage compared to automated controller design methods is that the control engineer can exploit all available a priori knowledge and expertise about the plant during the design process. As an assisting tool in manual loop shaping, we add a global optimization method, i.e. a genetic algorithm, where the objective function resembles as good as possible what the control engineer wants. As a result, the tuning process is substantially accelerated. The approach has been implemented in a Matlab-based control tuning tool showing good results

From Vision to Realtime Motion Control for the RoboCup Domain

In this paper, an overview is given of how the path from vision to motion has been developed in the TechUnited team. The vision module includes: (i) color calibration using a union of convex hulls to select an area in the 3D-colorspace, (ii) automatic calibration of the mapping from the camera image to the field via a genetic algorithm, (iii) self localization based on field lines. The output of the vision module is used by the motion module which includes: (i) vision and encoder sensor fusion by monitoring the drift caused by odometry, (ii) generating a motion path complying with the robots limitations to prevent wheel slippage, (iii) collocated motion control. In contrast to closing the loop on vision, our approach uses wheel encoders as the basis for motion control, which has several advantages such as less delay due to a higher sampling frequency. Vision is only used to compensate for slow drift caused by slip in the wheel-surface contact.

EFFICIENT IIR NOTCH FILTER DESIGN VIA MULTIRATE FILTERING TARGETED AT HARMONIC DISTURBANCE REJECTION

The present invention is directed toward a thermostable lipoprotein lipase capable of hydrolyzing triglycerides in lipoproteins to glycerol and fatty acids, a process for producing the thermostable lipoprotein lipase, and a blood triglyceride determining reagent containing the thermostable lipoprotein lipase. The thermostable lipoprotein lipase exhibits about 100% retention of the hydrolyzing activity when treated in a buffer having a pH of from bout 4 to 7 at about 60 DEG C. for about 15 minutes and a glycerol forming activity/fatty acid forming activity ratio of at least about 15%. The process comprises cultivating a thermophilic actinomycetes, particularly Streptomyces 7825 (FERM P-9983, FERM BP-2489 is cultivated to produce a thermostable lipoprotein lipase.

Realtime motion path generation using subtargets in a changing environment

In this work an algorithm is proposed for path planning in a changing environment. The algorithm is computationally cheap and generates a sub-optimal smooth path with bounds on the allowed velocity, acceleration and jerk. It outperforms potential field algorithms regarding both convergence and optimality. Furthermore, it is able to adapt fast in a changing environment in contrast with computationally more expensive methods, such as wavefront algorithms and global optimization methods. It is applicable to both holonomic systems and a class of nonholonomic systems

Design of a printhead alignment sensor for a temperature varying environment

First findings are presented of an absolute position sensor for active alignment of printheads with respect to the printer frame over a distance of one meter. A string is stretched along the guidance serving as an absolute reference. The developed sensor measures the position of the printhead relative to this string. It is cheap and it is robust for temperature variations in the order of tens of degrees. The target accuracy is 1 mum over a range of about 2 mm. Although only one measurement direction is of interest for the application, it can actually be used as a 2D sensor. If an extra sensor is added to the same string, a 4D sensor can be created

Tech United Eindhoven, Winner RoboCup 2014 MSL

In this paper we discuss improvements in mechanical, electrical and software design, which we did to become RoboCup 2014 world champion. Regarding hardware and control our progress includes first steps towards improved passing accuracy via velocity feedback control on the shooting lever. In terms of intelligent gameplay we have worked on creating possibilities for in-game optimization of strategic decisions. Via qr-code detection we can pass coaching instructions to our robots and with a basic machine learning algorithm success and failure after free-kicks is taken into account. In the final part of this paper we briefly discuss progress we have made in designing a four-wheeled soccer robot with a suspension system.

Active printhead alignment for Wide Format Printing Systems

In this work, an active printhead alignment method for wide format printing systems is proposed. Instead of tightening manufacturing tolerances, the misalignment of each printhead is measured with respect to the printer frame and is regulated using a voice coil actuator. This dramatically increases performance where costs of the alignment mechanism can be compensated by loosening the manufacturing tolerances which would otherwise be necessary. An experimental setup has been build for proof-of-concept. The experiments show promising results. Printheads can be aligned with an accuracy of 2 mum. The higher print accuracy results in a better print quality and enables additional features such as higher resolution printing (> 600 dpi) and adding redundant printheads for covering temporary nozzle disfunctioning.

Exploration of automatic controller synthesis for motion systems using genetic programming

Abstract In this paper a method for automatic controller synthesis based on Genetic Programming (GP) is presented. We propose a GP algorithm linked with Matlab/Simulink, a well known tool amongst control engineers. The GP algorithm performs its evolutionary steps to create controllers, whilst Matlab/Simulink evaluates these controllers for their appropriateness. The engineer no longer needs design rules, he only needs to specify both time- and frequency-domain requirements for the controller. Simulations have been carried out successfully, applying GP to find a linear controller for a fourth order motion system.

Tech United Eindhoven Middle Size League Winner 2016

The Tech United Eindhoven Mid-size league (MSL) team won the 2016 Championship in Leipzig. This paper describes the main progress we made in 2016 which enabled this success. Recent progress in software includes improved perception methods using combined omnivision of different robots and integrating the Kinect v2 camera onto the robots. To improve the efficiency of shots at the opponents’ goal, the obstacle detection is improved. During the tournament new defensive strategies were developed as an answer to the advanced attacking strategies that were seen during the round robins. Several statistics of matches during the tournament show the overall performance of Tech United at RoboCup 2016.