Control design for an overactuated wheeled mobile robot

In order to simulate road vehicles in a hardware-in-the-loop test setup, TNO has developed a wheeled mobile robot with independently driven and steered wheels. This robot is overactuated, i.e. the number of actuators exceeds the number of spatial degrees of freedom to be controlled. A position controller based on feedback linearization is presented. This controller takes the overactuatedness into account by using the so-called multicycle approach, which essentially regards the robot as a combination of independent unicycles. As a result, the robot is position controlled while the redundant actuators are used to compensate for weight transfer during acceleration and cornering

Control design for an overactuated wheeled mobile robot

In order to simulate road vehicles in a hardware-in-the-loop test setup, TNO has developed a wheeled mobile robot with independently driven and steered wheels. This robot is overactuated, i.e. the number of actuators exceeds the number of spatial degrees of freedom to be controlled. A position controller based on feedback linearization is presented. This controller takes the overactuatedness into account by using the so-called multicycle approach, which essentially regards the robot as a combination of independent unicycles. As a result, the robot is position controlled while the redundant actuators are used to compensate for weight transfer during acceleration and cornering

Ein validiertes Testverfahren für Notbremssysteme: Ergebnisse des ASSESS-Projekts

Im Rahmen des im 7. Forschungsrahmenprogramm der Europäischen Kommission geförderten Projekts „ASSESS“ wurde ein modulares Bewertungssystem für Systeme der aktiven Sicherheit erstellt und anhand von serienmäßigen Notbremssystemen getestet. Im Fahrversuch wurden Warnzeitpunkt, Bremszeitpunkt und Geschwindigkeitsreduktion serienmäßiger Fahrzeuge bestimmt. Dabei kamen zwei verschiedene Zielobjekte und vier verschiedene Ansätze zur Bewegung des Zielobjekts zum Einsatz. Die von den verschiedenen Testinstituten bestimmten Ergebnisse und die Streuungen der einzelnen Messungen sind vergleichbar – für eines der beiden Testfahrzeuge liegen die Streuungen, insbesondere bei Kennwerten für Warn- und Bremszeitpunkt, im Bereich von 2% des jeweiligen Mittelwertes. Die Streuungen der Beschwindigkeitsreduktion liegen höher, sind aber ebenfalls vergleichbar. Geringe Unterschiede zwischen zwei Gruppen von Testinstituten lassen sich durch Eigenschaften des verwendeten Zielobjekts beziehungsweise Eigenschaften des verwendeten Testfahrzeugs (RADAR-Kalibrierung) erklären. Zusätzlich bestimmte Warnzeitpunkte eines der beiden Fahrzeuge bei Auffahrt auf einen realen Pkw liegen gut im Bereich der mit synthetischen Zielobjekten gemessenen Zeiten. Aus diesen Erkenntnissen wird abgeleitet, dass das Testverfahren grundsätzlich geeignet ist, reproduzierbar und wiederholbar die Bremsleistung eines mit Notbremsfunktion ausgerüsteten Fahrzeugs zu messen. Erreichte Wiederholgenauigkeiten von ± 1 km/h für die jeweiligen Geschwindigkeiten und ± 30 cm für den seitlichen Abstand haben sich als ausreichend erwiesen. Die in Feld- und Simulatorversuch ermittelte Fahrerreaktion, die durch einen relativ geringen Bremspedalkraftgradienten gekennzeichnet ist, hat sich als simulierte Fahrerreaktion so nicht bewährt. Wesentlicher Grund dafür ist die Regelgüte und die erforderliche Abstimmungsarbeit herkömmlicher Bremspedalaktorik. Das Konsortium ist sich aber einig darin, dass eine simulierte Fahrerreaktion erforderlich ist, um die Sicherheitswirkung eines Notbremssystems umfassend zu bewerten. Ansätze hierfür könnten die in anderen Konsortien entwickelten Fahrerreaktionen sein. Detailliertere Ergebnisse des ASSESS-Projekts finden sich auf der Website www.assessproject.eu

Pre-crash evaluation: final status

Based on the test scenarios and target specifications as described in the ASSESS deliverable D4.2 “Draft test and assessment protocol” a second series of pre-crash evaluation tests have been carried out by BAST, IDIADA, TNO and DAIMLER. Like in the first series of test conducted by BASt and IDIADA within the second series only rear-end manoeuvres were conducted. This was in line with the specifications of the test vehicles and the available laboratory equipment. The main objective of the second series was to check the reproducibility and repeatability of the specified test program and the capability of the various laboratories with the newly implemented laboratory updates as realized within the ASSESS project

The Association between Diabetes Medication Use and Tumour Characteristics at Diagnosis in Patients with Urothelial Carcinoma: A Retrospective Registry-Based Study1

BACKGROUND: Observational studies indicate a potential association between diabetes medication use and aggressiveness of bladder cancer. OBJECTIVE: The objective is to exploratively study the association between diabetes medication use, as proxy for diabetes, and cancer characteristics of urothelial carcinoma at diagnosis. Furthermore, differences in associations between specific types of diabetes medication are studied. METHODS: The association between use of diabetes medication and urothelial carcinoma (UC) characteristics at diagnosis is studied. A retrospective registry-based study among UC patients in the Netherlands was performed for which two large linked registries from PHARMO and IKNL were used. Patients diagnosed with UC between 2000 and 2016 and no previous cancer were included in this study. In this study, 1,168 UC patients who were diabetes medication users were included as well as 3,609 non-users. Conditional logistic regression analysis was performed to determine odds ratios comparing cancer characteristics between different types of diabetes medication users to non-users. RESULTS: Noninsulin antidiabetic drugs (NIAD) use was associated with a muscle-invasive type of UC compared to non-users (OR = 1.31, 95%CI: 1.10-1.55 for T2+ versus Ta) as well as a poorly differentiated tumour (OR = 1.31, 95%CI: 1.07-1.59 for poorly versus well differentiated tumours). CONCLUSION: Users of diabetes medication are potentially more likely to be diagnosed with a more aggressive tumour than non-users; however, lifestyle factors could not be adjusted for

Pre-crash performance of collision mitigation and avoidance systems: results from the ASSESS project

Integrated vehicle safety systems that combine elements from primary and secondary safety have a high potential to improve vehicle safety, due to their ability to influence crash conditions and/or to adapt to these crash conditions. So far no standard evaluation procedures have been developed and implemented. The main goal of the ASSESS project is to develop harmonized and standardized assessment procedures for related collision mitigation and avoidance systems. Procedures are developed for: · Driver behavior evaluation; · Pre-crash system performance evaluation; · Crash performance evaluation; · Socio-economic assessment. This paper presents the activities related to the “Pre-Crash evaluation”. The objective is to provide a tool box for the specific evaluation of the pre-crash performance of collision mitigation and avoidance systems and their contribution to the overall system performance