Kirsti Sääskilahti

Remote navigation of a mobile robot in an RFID-augmented environment

In the current article, we address the problem of constructing radiofrequency identification (RFID)-augmented environments for mobile robots and the issues related to creating user interfaces for efficient remote navigation with a mobile robot in such environments. First, we describe an RFID-based positioning and obstacle identification solution for remotely controlled mobile robots in indoor environments. In the robot system, an architecture specifically developed by the authors for remotely controlled robotic systems was tested in practice. Second, using the developed system, three techniques for displaying information about the position and movements of a remote robot to the user were compared. The experimental visualization techniques displayed the position of the robot on an indoor floor plan augmented with (1) a video view from a camera attached to the robot, (2) display of nearby obstacles (identified using RFID technology) on the floor plan, and (3) both features. In the experiment, test subjects controlled the mobile robot through predetermined routes as quickly as possible avoiding collisions. The results suggest that the developed RFID-based environment and the remote control system can be used for efficient control of mobile robots. The results from the comparison of the visualization techniques showed that the technique without a camera view (2) was the fastest, and the number of steering motions made was smallest using this technique, but it also had the highest need for physical human interventions. The technique with both additional features (3) was subjectively preferred by the users. The similarities and differences between the current results and those found in the literature are discussed.

Needs and user acceptance of older adults for mobile service robot

The population in the world is getting older and the need for the new technical solutions supporting independent life of elderly people is increasing. The needs and expectations of the senior people are the most important factors that define the acceptance of such solutions. In the current paper, we study qualitatively with few older adults how a service robot with a multimodal control interface can support people in this phase of life. The results reveal that multimodality of the control interface and functionalities involving safety and entertainment are very important for end-user acceptance. The user acceptance increases if the available functionalities can be customized for different users and if the commands for both screen-based and voice-based control use the same words and phrases. This approach also allows to decrease the memory load on the user. The possibility to customize the interfaces could open broad possibilities to use the robot also by the disabled people.

Visual perception of digital holograms on autostereoscopic displays

In digital holography we often capture optically a 3D scene and reconstruct the perspectives numerically. The reconstructions are routinely in the form of a 2D image slice, an extended focus image, or a depth map from a single perspective. These are fundamentally 2D (or at most 2.5D) representations and for some scenes are not certain to give the human viewer a clear perception of the 3D features encoded in the hologram (occlusions are not overcome, for example). As an intermediate measure towards a full-field optoelectronic display device, we propose to digitally process the holograms to allow them to be displayed on conventional autostereoscopic displays.

Evaluation of perceived quality attributes of digital holograms viewed with a stereoscopic display

Holography is a well-known technique for sensing and displaying real-world three-dimensional (3D) objects. Digital holograms have been successfully displayed on conventional stereoscopic displays allowing research into perception of quality of 3D holographic data. We do know that quality is enhanced if reconstructions of digital holograms are displayed with conventional stereoscopic displays rather than with a regular two-dimensional (2D) screen. However, it is not known how different attributes (e.g. noise, blur, and perceived depth) and the viewers subjective perception of quality are related. In this study, we show how 13 viewers evaluated these attributes and the visual quality of five holograms displayed stereoscopically.

Techniques for location selection on a mobile device

In this paper we present techniques for selecting ones current location in mobile location-based systems. We present Locawe (Location-aware System Platform) and four alternative location selection techniques, which are physical selection using RFID technology, automatic selection based on GPS coordinates, selection from a mobile map with a stylus, and a textual selection technique involving a virtual keyboard and a selection list. These techniques have been tested in real mobile applications.

Collecting and visualizing wireless geosensor data using mobile devices

Monitoring the state of the environment has traditionally based on remote monitoring systems maintained by official organizations and institutions. A development of mobile and ubiquitous computing opens new possibilities to collect geosensor data directly from users environment as in situ measurements. In the current paper, we describe a geosensor network (GSN) solution between mobile devices and wireless geosensor nodes based on usability criteria. The results showed that it is possible to create in situ measurements which are reliable and robust enough even in extreme conditions such as low temperatures with ice and snow. Users experienced that the developed GSN solution was easy to use and the visualization of the collected data on the small screen of mobile device was evaluated as a level of satisfactory. The amount and speed of feedback about users actions was found important in this data gathering system. In addition, the overall usability of the system correlated with system feedback. As a result, we suggest that this solution is usable and robust even in extreme winter conditions. The challenge is still in energy consumption which was not in the centre of this research.

Stereo perception of reconstructions of digital holograms of real-world objects

In digital holography a 3D scene is captured optically and often the perspectives are reconstructed numerically. In this study we digitally process the holograms to allow them to be displayed on autostereoscopic displays. This study is conducted by subjective visual perception experiments comparing single reconstructed images from left and right perspective to the resulting stereo image.

Displaying digital holograms of real-world objects on a mobile device using tilt-based interaction

Holography is a well-known technique for sensing and displaying real-world three-dimensional (3D) objects. Reconstructions from digital holograms are typically displayed with regular two-dimensional (2D) screens and therefore lot of the 3D specific information is not passed on to the viewer during the display process. Mobile devices have interesting possibilities for displaying 3D data interactively. In this study, we show how nine viewers evaluated hologram reconstructions with a tilt based display system incorporated into a mobile device.