Shared Control of Mobile Robots Using Model Predictive Control

With the world constantly driving towards attaining complete autonomy, there is still a major question of safety when it comes to trusting a machine completely. Autonomous systems of today also do not have the ability to perform flawlessly in an environment that is cluttered and unstructured. This calls for the need of having a human operate the machine at all times either remotely via tele-operation methods or by being physically present alongside the machine. With tele-operation of remote systems, the cognitive load required from the human operator is high, while also the perception of the remote systems environment is low. This can cause many undesirable human errors causing damage to machinery. For example, tele-operating a forestry machine in a forest can be a very daunting task as there will be many trees and not all trees around the machine can be seen by the operator during remote tele-operation. With this in context, a few industries and sectors have now largely started research with using shared control methodologies to aid their machine in tele-operation tasks. This thesis proposes a shared control methodology to provide a certain level of autonomy to the machine while still allowing the human operator to always be in control. The proposed methodology uses a Model predictive controller as the base controller to control the robot and perform obstacle avoidance tasks. The robot considered for implementation is a differential drive mobile robot, in specific the MiR 100 from Mobile Industrial Robots. The key motivation behind the thesis is to evaluate the performance of the shared control approach against a manual tele-operation task, to better understand the advantages and possible disadvantages of using a shared control strategy. The proposed strategy is implemented using the CasADi optimization toolbox on Matlab and tested through user testings. The results obtained from the user test prove that shared control can largely help in improving the safety of the system, but not so much with performance, at least not with the proposed methodology

A within-person analysis of sales self-efficacy: antecedents and consequences of self-efficacy change

Authors are presently providing implications to practitioners suggesting that enhancing self-efficacy beliefs are universally beneficial in regard to salesperson performance. However, despite advice being provided as to how to enhance the self-efficacy beliefs of salespeople, there is very little empirical research on the drivers of self-efficacy. Extant literature studies only the antecedents to, and consequences of, self-efficacy via an examination how salespeople differ in their level of self-efficacy (i.e., at the between-person level). Yet, how self-efficacy beliefs can be influenced, and how change in self-efficacy at the individual level (i.e., at the within-person level) influences subsequent effort and salesperson performance, remain unexplored. Therefore, the aim of the present study is to understand the antecedents to, and consequences of, self-efficacy change. A conceptual framework outlining how self-efficacy can demonstrate contradictory relationships with effort and salesperson performance at the between-person and within-person levels of analysis is presented. Using a sample of business-to-business salespeople in the United States of America, this conceptual model is analyzed using longitudinal multilevel modeling. The findings show that salespeople with higher self-efficacy beliefs put in greater effort and perform better. However, the findings also show that increases in a salesperson’s self-efficacy can reduce subsequent effort allocation and salesperson performance; further, that this negative influence of self-efficacy increases on effort allocation is moderated by perceived competitive intensity. Emotional exhaustion also reduces the positive influence of effort allocation on performance at both levels of analysis. Intra-individual self-efficacy trajectories are positively influenced by longer-term past performance and positive (manager) feedback; conversely, sales anxiety negatively influences self-efficacy trajectories. This doctoral thesis helps managers to understand how the self-efficacy beliefs of their salespeople can be manipulated, while also highlighting to managers that they should be conscious of the potential detrimental effects of self-efficacy on the subsequent effort allocation and performance of their salespeople. In addition, the key implications of the study for sales and marketing theory are provided. Research limitations and avenues for future research conclude the thesis

Towards A Multidimensional Perspective on Shared Autonomy

Schilling M, Kopp S, Wachsmuth S, et al. Towards A Multidimensional Perspective on Shared Autonomy. In: Proceedings of the AAAI Fall Symposium Series 2016, Stanford (USA). 2016

The effects of safety culture on project performance in high risk industries

Projects are undertaken at Koeberg Nuclear Power Station in South Africa to enhance safety and to contribute to the continuity of power supply in the country. These projects are undertaken in an industry that is regarded as a high risk due to the potential consequence of a nuclear accident. Focus is thus placed on safety culture to prevent such accidents from taking place. Since safety is a key performance indicator in these high-risk industries, and projects are undertaken to improve the overall performance of such organizations, the role which safety culture has on project performance would be of interest. This study investigates how safety culture influences project performance and identifies the respective elements that collectively interact in contributing towards successful project outcomes in the context of Koeberg Nuclear Power Station. The study has found that - Safety culture plays a vital role in safety performance which is a recognized performance indicator of projects in high risk industries. Safety culture itself was found to consist of the elements of safety performance, personal values to safety, safety leadership, safety related interpersonal relations, proactivity to safety, commitment to safety and continuous improvements to safety. These elements with emphasis on safety were related to the project management knowledge areas of Time, Scope, Risk, Quality, Human Resource and Communication Management. The project managers competencies are also included amongst these elements which respectively interact with one another to influence the level of safety culture in a project. The study has revealed that these elements should be worked at by all departments involved in a project to allow the required performance criteria to be achieved. In addition, it reveals that a good safety culture provides flexibility in addressing changing requirements in a project

Recognition of romantic relationship danger signs.

Romantic relationships are a strong source of personal well being for many individuals, with unhealthy partnerships promoting greater distress and dissatisfaction. Several variables have been identified in the literature as “danger signs” which seem to predict current and/or future relational discord. These danger signs are expressed within couple communication (such as invalidation or escalation) and behaviors (such as physical violence and controlling actions). However, little is known about individual variability in the ability and willingness to accurately identify these danger signs. The current study explores this gap in the literature. Specifically, seven video vignettes of interactions between two partners (actors) were presented to participants, which depicted specific danger signs. Participants were then asked what they noticed, and responses were coded for identification of danger signs. Further more, participants also indicated their hypothetical level of commitment to the relationship following each clip. Participants provided responses for measures of adult attachment, experiences of intimate partner violence and emotional control in romantic relationships, engagement in negative relational maintenance behaviors, level of relational thoughtfulness and relational unawareness, past traumatic experiences, and global coping style. Generally, it was hypothesized that physical violence would be recognized at higher rates as compared to negative relational maintenance behavior danger signs, and these would be recognized at greater rates as compared to communication danger signs. It was predicted that those with greater insecure attachment would recognize danger signs more quickly (as compared to those with higher ratings of secure attachment) as the videos were presented with greater overt expression. It was also hypothesized that those with anxious attachment would report consistent commitment across videos, whereas those with greater avoidant attachment ratings would endorse lower levels of commitment. In addition, mediation models were proposed, wherein attachment would predict commitment ratings through coping strategy (active or passive coping). Lastly, it was predicted that higher ratings of relational awareness would be associated with greater danger sign recognition and lower levels of commitment. Results of the study supported the broad hypothesis that physical violence was recognized at a higher rate as compared to negative relational maintenance behaviors, and communication danger signs were recognized at the lowest level. However, no other significant associations were found within the proposed models. Still, intimate partner violence experiences were related to higher rates of danger sign recognition, as was relational thoughtfulness. Conclusions and implications are offered for improved methods of data collection, and possible explanations for the non-significant findings