Handwheel Force Feedback for Lanekeeping Assistance: Combined Dynamics and Stability

2005 ◽  
Vol 128 (3) ◽  
pp. 532-542 ◽  
Author(s):  
Joshua P. Switkes ◽  
Eric J. Rossetter ◽  
Ian A. Coe ◽  
J. Christian Gerdes

Lanekeeping assistance could save thousands of lives each year by maintaining lane position in the absence of driver steering commands. In order to work smoothly with the driver, handwheel force feedback must be an integral part of such a system. Here we combine force feedback with a lanekeeping controller based on lateral and heading error. In addition to force feedback replicating the feel in a conventional vehicle, the force can be based on the level of lanekeeping assistance being given. This coupling of the force feedback and assistance systems can destabilize the vehicle if not designed properly. Linear modeling verified by experiments shows the effect of varying the gains on both the force feedback and the lanekeeping assistance itself. In this analysis we show that within a range of values that feel reasonable to the driver, changes to the lanekeeping controller or force feedback can have marked effects on the response of the vehicle. It also shows that stability of the system can be ensured by injecting artificial damping or reproducing the on-center characteristics of a conventional vehicle. The analysis allows the force feedback designer to determine a range of stable force feedback gains, from which a set most acceptable to the driver can be chosen.

Author(s):  
Ronald R. Mourant ◽  
Praveen Sadhu

Eight participants drove a fixed base simulator using both spring-loaded and force feedback steering wheels. Their route included curves of 100, 200 and 300 radii of curvature, and two freeway style exit ramps that were sloped, banked and, had changing radii of curvature. Both mean and variance of lane position were calculated. There were no differences in terms of mean and variance of lane position between the steering wheels when driving on straight road segments. Lane position variance was significantly greater when driving on the 100 meter curves then when driving of the 200 and 300 meter curves. Drivers “hugged” left hand curves more when using the force feedback steering wheel as indicated by their average lane position being significantly more to the left. On the two right hand exit ramps, drivers drove significantly more to the left when using the force feedback steering wheel. Subjects rated the force feedback steering wheel higher in terms of realism, maneuverability, and vehicle control on a post-experiment questionnaire.


2019 ◽  
Vol 18 (2) ◽  
pp. 106-111
Author(s):  
Fong-Yi Lai ◽  
Szu-Chi Lu ◽  
Cheng-Chen Lin ◽  
Yu-Chin Lee

Abstract. The present study proposed that, unlike prior leader–member exchange (LMX) research which often implicitly assumed that each leader develops equal-quality relationships with their supervisors (leader’s LMX; LLX), every leader develops different relationships with their supervisors and, in turn, receive different amounts of resources. Moreover, these differentiated relationships with superiors will influence how leader–member relationship quality affects team members’ voice and creativity. We adopted a multi-temporal (three wave) and multi-source (leaders and employees) research design. Hypotheses were tested on a sample of 227 bank employees working in 52 departments. Results of the hierarchical linear modeling (HLM) analysis showed that LLX moderates the relationship between LMX and team members’ voice behavior and creative performance. Strengths, limitations, practical implications, and directions for future research are discussed.


2010 ◽  
Author(s):  
Nathan Medeiros-Ward ◽  
Janelle Seegmiller ◽  
Joel Cooper ◽  
David Strayer
Keyword(s):  

2001 ◽  
Vol 40 (02) ◽  
pp. 51-58 ◽  
Author(s):  
H. Schliephake ◽  
van den Hoff ◽  
W. H. Knapp ◽  
G. Berding

Summary Aim: Determination of the range of regional blood flow and fluoride influx during normal incorporation of revascularized fibula grafts used for mandibular reconstruction. Evaluation, if healing complications are preceded by typical deviations of these parameters from the normal range. Assessment of the potential influence of using “scaled population-derived” instead of “individually measured” input functions in quantitative analysis. Methods: Dynamic F-l 8-PET images and arterialized venous blood samples were obtained in 11 patients early and late after surgery. Based on kinetic modeling regional blood flow (K1) and fluoride influx (Kmlf) were determined. Results: In uncomplicated cases, early postoperative graft K1 - but not Kmlf -exceeded that of vertebrae as reference region. Kmn values obtained in graft necrosis (n = 2) were below the ranges of values observed in uncomplicated healing (0.01 13-0.0745 ml/min/ml) as well as that of the reference region (0.0154-0.0748). Knf values in mobile non-union were in the lower range - and those in rigid non-union in the upper range of values obtained in stable union (0.021 1-0.0694). If scaled population-derived instead of measured input functions were used for quantification, mean deviations of 23 ± 17% in K1 and 12 ± 16% in Kmlf were observed. Conclusions: Normal healing of predominantly cortical bone transplants is characterized by relatively low osteoblastic activity together with increased perfusion. It may be anticipated that transplant necrosis can be identified by showing markedly reduced F− influx. In case that measured input functions are not available, quantification with scaled population-derived input functions is appropriate if expected differences in quantitative parameters exceed 70%.


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