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131	Undersökning och validering av lågprissystem för kraftmätning : Hur bra kan en Wii Balance Board bli med ny elektronik? / Analysis and validation of low-price system for force measurement : How good can a Wii Balance Board become with new electronics? Mustafa, Rahand January 2024 (has links) Behovet för kraftplattor idag växer inom idrotts- och sportsammanhang såväl som inom medicinska sektorn. Problemet med majoriteten av kraftplattorna på marknaden idag är att de är dyra, samt stora och tunga. På Kungliga tekniska högskolans skola för medicinteknik och hälsosystem utvecklades en kraftplatteprototyp med Wii Balance Board i hopp om att vara billigare och kunna användas i medicinskt, terapeutiskt och idrottssyfte. Enligt konstruktören och uppdragsgivaren finns det ett behov att göra om denna prototyp genom att undersöka möjligheten till att använda komponenter som är billiga, tillgängliga för allmänheten men samtidigt är noggrann och pålitlig i mätningarna. I detta arbete undersöks möjligheterna samt konstrueras två prototyper för jämförelse och analys för att säkerställa pålitlighet och noggrannhet. Två kraftplatteprototyper utvecklades, ena prototypen använde en HX711 som AD- omvandlare mellan lastcellerna på Wii Balance Boarden och ESP32 mikrokontrollern och den andra en AD7124-8 som AD-omvandlare mellan lastcellerna och ESP32 mikrokontrollern. Lastcellerna kopplades till dessa AD-omvandlare som sedan kopplades till en ESP32 mikrokontroller som tog emot datat och presenterade det i Arduino IDE samt i applikationen Blynk. Resultatet av arbetet visade att båda prototyperna är pålitliga och noggranna i viktmätningarna vid låga samplingsfrekvenser, men att AD7124-8 är betydligt mycket mer lämplig i idrott och medicinska syften på grund av dess höga samplingsfrekvens samt filtreringsalternativ för brus då det i dessa sammanhang är viktigt att kunna mäta snabba kraftförändringar. / The need for force plates is increasing today in the sports and medicine industry. The challenges with force plates are the price point and the immobility of them, they are often big and heavy. A force plate prototype with a Wii Balance Board was developed at Royal Institute of Technology’s school for biomedical engineering and health systems with the hope of achieving a cheaper solution that could be used in medical research and the sports industry. According to the constructor of the force plate prototype, there is a need to redo this prototype by doing research of using cheaper and more readily available components but at the same time be precise and trustworthy in measurements. The possibilities are evaluated in this work and two prototypes are constructed. Two force plate prototypes were constructed, one of them used a HX711 AD-converter between the load cells of the Wii Balance Board and the ESP32 microcontroller and the other prototype used a AD7124-8. The load cells connected to the AD-converters and then to the ESP32 which showed the output values in the serial monitor of Arduino IDE and in the Blynk app. The results of the tests conducted showed that both prototypes provided a reliable and precise measurement of weight at low sample rates. But that the AD7124-8 was considerably more suitable for medicine research and sports research due to its capability to sample at high frequencies and noise filtering options, which is crucial when wanting to detect rapid changes in force. Force plate Wii balance board analog-to-digital converter Arduino Wi-Fi load cell sports technology rehabilitation calibration validation ESP32 HX711 AD7124-8 Kraftplatta Wii balance board analog till digitalomvandlare Arduino Wi-Fi lastcell idrottsteknologi rehabilitering kalibrering validering ESP32 HX711 AD7124-8 Embedded Systems Inbäddad systemteknik
132	Měřič odstupu signálu od šumu obrazových signálů / BER Meter for Video Signals Šimoník, Petr January 2008 (has links) The diplomma thesis is dealing with possibilities of Signal to noise ratio measurement by method, which is based on direct measurement. It is chosen the most suitable method – signal and noise separation to two different parallel signal branches, where is measured signal strength in one branch and root mean square value in the other. The thesis is consisted of a concept of detail block scheme of Signal to noise ratio meter, which was designed in terms of theoretical knowledge. Particular functional blocks were circuit-designed, the active and passive parts were chosen and their function were described. There were made simulation and displayed input and output time flows. There is designed the whole connection of engineered Signal to noise ratio meter in the last part of my thesis. The double-sided board of printed circuit is contained too. It was created simple programme for supervisor micro-processor. Thereby were constructed complete bases for realization.
133	Development of Sensors and Microcontrollers for Underwater Robots Jebelli, Ali January 2014 (has links) Nowadays, small autonomous underwater robots are strongly preferred for remote exploration of unknown and unstructured environments. Such robots allow the exploration and monitoring of underwater environments where a long term underwater presence is required to cover a large area. Furthermore, reducing the robot size, embedding electrical board inside and reducing cost are some of the challenges designers of autonomous underwater robots are facing. As a key device for reliable operation-decision process of autonomous underwater robots, a relatively fast and cost effective controller based on Fuzzy logic and proportional-integral-derivative method is proposed in this thesis. It efficiently models nonlinear system behaviors largely present in robot operation and for which mathematical models are difficult to obtain. To evaluate its response, the fault finding test approach was applied and the response of each task of the robot depicted under different operating conditions. The robot performance while combining all control programs and including sensors was also investigated while the number of program codes and inputs were increased. AUV Autonomous Underwater Vehicles ADC Analog to Digital Converter Cd Drag coefficient of the object DOF Degree of Freedom KT Thrust coefficient Fd Force of drag g Acceleration of gravity h Height of the fluid above the object KQ Torque coefficient mb Buoyant mass NN Neural network P Proportional controller PI Proportional-integral controller PID ρ Density of the fluid Q Torque of the propeller ROV Remotely Operated Vehicles RPM Speed of the motor or propeller SDO Serial data output SMC Sliding mode control Measured thrust T° Temperature v AV Advance speed of the propeller

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