Providing real walking in virtual environments remains a challenge because of space, setup, and t... more Providing real walking in virtual environments remains a challenge because of space, setup, and tracking system requirements. With the help of redirected walking (RDW), natural and unconstrained walking in virtual environments has become possible – without using mechanical locomotion devices – by manipulating the user's real world trajectory such that he remains within the boundaries of the walkable space. Nevertheless, typical home or office environments do not provide sufficient space or a suitable room which is free of obstacles. This paper presents an approach that combines RDW with a low-cost and user-worn tracking approach based on simultaneous localization and mapping (SLAM). I.e. learning the environment with the walkable area, tracking the user's viewpoint, and RDW is done on the fly without any prior setup, without preparing a room, and without setting up a tracking system. This allows ad hoc free walking in virtual environments even within dynamic and cluttered physical rooms, where the walkable area is of arbitrary shape. Furthermore, by combining SLAM and a planning RDW controller , this approach has the potential to provide the best free walking experience for any given physical environment.
Nowadays, buildings or production facilities are designed using specialized design software and b... more Nowadays, buildings or production facilities are designed using specialized design software and building information modeling tools help to evaluate the resulting virtual mock-up. However, with current, primarily desktop based tools it is hard to evaluate human factors of such a design, for instance spatial constraints for workforces. This paper presents a new tool for factory planning and evaluation based on virtual reality that allows designers, planning experts, and workforces to walk naturally and freely within a virtual factory. Therefore, designs can be checked as if they were real before anything is built.
2010 AAAI Spring Symposium, Embedded Reasoning: Intelligence in Embedded Systems, 2010
On interactive surfaces, an accurate calibration is crucial for a precise user interaction. Today... more On interactive surfaces, an accurate calibration is crucial for a precise user interaction. Today, geometric distortions are eliminated by a static calibration. However, this calibration is specific to a user’s posture and parallax distortions occur if this changes (i.e. when the user moves in front of the screen or multiple users take turns). In this paper, we describe an approach to apply Partially Observable Markov Decision Processes (POMDPs) for automatic online re-calibration to cope with changing viewpoints, which are indicated by uncertain observations of the user’s interaction quality on the surface.
We present InfrActables, a wireless technology for human computer interaction devices. It allows ... more We present InfrActables, a wireless technology for human computer interaction devices. It allows multiple users to interact simultaneously on back-projection displays. It recognizes each device's position, orientation, and identification, but also enables the tools to communicate their states to the application that the user interacts with. This makes it possible to build complex interaction devices for direct manipulation with buttons,
ASME 2009 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, 2009
This paper presents a novel approach to estimate a person’s intended locomotion target. This esti... more This paper presents a novel approach to estimate a person’s intended locomotion target. This estimation is based on models of human locomotion and the finding that locomotion is planned such that the movement minimizes a certain cost function. Using such a cost function, we calculate the expected costs for a path trajectory to a number of possible targets, and make an estimation of a person’s intended target based on changes in these expected costs in relation to the cost of the path up to this point.
14th International Conference on Computers Helping People with Special Needs
This Special Thematic Session describes the elements of an IT system that allows for a better int... more This Special Thematic Session describes the elements of an IT system that allows for a better integration of blind people in a MindMap brainstorming session together with sighted users. Software components will be introduced that convert the parallel information visualization to a serialized information representation, which will then be output on a special blind user interface using screen reader and Braille display. Moreover, non-verbal communication elements are another important carrier of information, which also need to be captured and displayed to the blind user. Thus, this session also describes the necessary hardware components and the overall setup, which will allow for a more efficient teamwork in such a mixed team.
Volume 2: 29th Computers and Information in Engineering Conference, Parts A and B, 2009
A common problem in optical motion capture is the so-called missing marker problem. The occlusion... more A common problem in optical motion capture is the so-called missing marker problem. The occlusion of markers can lead to significant loss of tracking accuracy unless continuous data flow is guaranteed by computationally demanding interpolation or extrapolation schemes. Since interpolation algorithms require data sampled before and after an occlusion, they cannot be used for real-time applications. Extrapolation algorithms only require data sampled before an occlusion. Other algorithms require statistical data and are designed for post-processing. In order to bridge sampling gaps caused by occluded markers and hence to improve 3D real-time motion capture, we suggest a real-time extrapolation algorithm. The realization of this prediction algorithm does not need statistical data or rely on an underlying cinematic human model with pre-defined marker distances. Under the assumption that natural motion can be linear, circular, or a linear combination of both, a prediction method is suggested and realized. The paper presents linear and circular movement measurements for use when a marker is briefly lost. The suggested extrapolation method seems to behave well for a reasonable number of frames, not exceeding 200 milliseconds.
2010 International Conference on Cyberworlds, 2010
On interactive surfaces, a precise calibration of the tracking system is necessary for an exact u... more On interactive surfaces, a precise calibration of the tracking system is necessary for an exact user interaction. So far, common calibration techniques focus on eliminating geometric distortions. This static calibration is only correct for a specific viewpoint of one single user and parallax error distortions still occur if this changes (i.e. if the user moves in front of the digital screen). In order to overcome this problem, we present an empirical model of the user's position and movement in front of a digital screen. With this, a model predictive controller is able to correct the parallax error for future positions of the user. We deduce the model's parameters from a user study on a large interactive whiteboard, in which we measured the 3D position of the user's viewpoint during common interaction tasks
We present InfrActables, a wireless technology for human computer interaction devices. It allows ... more We present InfrActables, a wireless technology for human computer interaction devices. It allows multiple users to interact simultaneously on back-projection displays. It recognizes each device’s position, orientation, and identification, but also enables the tools to communicate their states to the application that the user interacts with. This makes it possible to build complex interaction devices for direct manipulation with buttons, sliders, and other input capabilities. The technology was developed for a computer-supported environment, allowing multiple users to interact simultaneously on a surface using multiple styli and other user input devices. The principle of operation is not limited to two-dimensional surfaces, three-dimensional user input devices can also profit from its advantages.
Smart Structures and Materials 1999: Smart Structures and Integrated Systems, Mar 1999
Haptic rendering is the process of computing and generating forces in response to user interactio... more Haptic rendering is the process of computing and generating forces in response to user interactions with virtual objects. The interaction modality of haptic feedback gains more and more of importance for simulation tasks in virtual environments. However there are only very few portable haptic interfaces, with which the user can experience in a natural way the sensation of force feedback. The scope of this paper is to present a new portable haptic interface using shape memory alloy wires as actuators. Shape memory alloys (SMA), and especially the nickel-titanium compositions, offer a number of engineering properties available in no other material. The ability to respond with significant force and motion to small changes in ambient temperature and the capability to convert heat energy into mechanical work provide the designer with a new array of possibilities. Beside some application specific characterization of the actuator material with respect to energy consumption and dynamic behavior for loading, the mechanical layout of the interface is discussed in detail. To realize a light and compact design of the interface, a flexure hinge is considered as an essential part of interface.
In a collaborative environment, non-verbal communication elements carry important contents. These... more In a collaborative environment, non-verbal communication elements carry important contents. These contents are partially or completely lost in remote collaboration. This paper presents a system to address this issue by tracking pointing gestures, the main non-verbal communication element prevalent in such meetings. The setup employs a touchscreen tabletop computer system for representing the visual content of the meeting, together with three motion trackers for tracking the pointing gestures.
Providing real walking in virtual environments remains a challenge because of space, setup, and t... more Providing real walking in virtual environments remains a challenge because of space, setup, and tracking system requirements. With the help of redirected walking (RDW), natural and unconstrained walking in virtual environments has become possible – without using mechanical locomotion devices – by manipulating the user's real world trajectory such that he remains within the boundaries of the walkable space. Nevertheless, typical home or office environments do not provide sufficient space or a suitable room which is free of obstacles. This paper presents an approach that combines RDW with a low-cost and user-worn tracking approach based on simultaneous localization and mapping (SLAM). I.e. learning the environment with the walkable area, tracking the user's viewpoint, and RDW is done on the fly without any prior setup, without preparing a room, and without setting up a tracking system. This allows ad hoc free walking in virtual environments even within dynamic and cluttered physical rooms, where the walkable area is of arbitrary shape. Furthermore, by combining SLAM and a planning RDW controller , this approach has the potential to provide the best free walking experience for any given physical environment.
Nowadays, buildings or production facilities are designed using specialized design software and b... more Nowadays, buildings or production facilities are designed using specialized design software and building information modeling tools help to evaluate the resulting virtual mock-up. However, with current, primarily desktop based tools it is hard to evaluate human factors of such a design, for instance spatial constraints for workforces. This paper presents a new tool for factory planning and evaluation based on virtual reality that allows designers, planning experts, and workforces to walk naturally and freely within a virtual factory. Therefore, designs can be checked as if they were real before anything is built.
2010 AAAI Spring Symposium, Embedded Reasoning: Intelligence in Embedded Systems, 2010
On interactive surfaces, an accurate calibration is crucial for a precise user interaction. Today... more On interactive surfaces, an accurate calibration is crucial for a precise user interaction. Today, geometric distortions are eliminated by a static calibration. However, this calibration is specific to a user’s posture and parallax distortions occur if this changes (i.e. when the user moves in front of the screen or multiple users take turns). In this paper, we describe an approach to apply Partially Observable Markov Decision Processes (POMDPs) for automatic online re-calibration to cope with changing viewpoints, which are indicated by uncertain observations of the user’s interaction quality on the surface.
We present InfrActables, a wireless technology for human computer interaction devices. It allows ... more We present InfrActables, a wireless technology for human computer interaction devices. It allows multiple users to interact simultaneously on back-projection displays. It recognizes each device's position, orientation, and identification, but also enables the tools to communicate their states to the application that the user interacts with. This makes it possible to build complex interaction devices for direct manipulation with buttons,
ASME 2009 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, 2009
This paper presents a novel approach to estimate a person’s intended locomotion target. This esti... more This paper presents a novel approach to estimate a person’s intended locomotion target. This estimation is based on models of human locomotion and the finding that locomotion is planned such that the movement minimizes a certain cost function. Using such a cost function, we calculate the expected costs for a path trajectory to a number of possible targets, and make an estimation of a person’s intended target based on changes in these expected costs in relation to the cost of the path up to this point.
14th International Conference on Computers Helping People with Special Needs
This Special Thematic Session describes the elements of an IT system that allows for a better int... more This Special Thematic Session describes the elements of an IT system that allows for a better integration of blind people in a MindMap brainstorming session together with sighted users. Software components will be introduced that convert the parallel information visualization to a serialized information representation, which will then be output on a special blind user interface using screen reader and Braille display. Moreover, non-verbal communication elements are another important carrier of information, which also need to be captured and displayed to the blind user. Thus, this session also describes the necessary hardware components and the overall setup, which will allow for a more efficient teamwork in such a mixed team.
Volume 2: 29th Computers and Information in Engineering Conference, Parts A and B, 2009
A common problem in optical motion capture is the so-called missing marker problem. The occlusion... more A common problem in optical motion capture is the so-called missing marker problem. The occlusion of markers can lead to significant loss of tracking accuracy unless continuous data flow is guaranteed by computationally demanding interpolation or extrapolation schemes. Since interpolation algorithms require data sampled before and after an occlusion, they cannot be used for real-time applications. Extrapolation algorithms only require data sampled before an occlusion. Other algorithms require statistical data and are designed for post-processing. In order to bridge sampling gaps caused by occluded markers and hence to improve 3D real-time motion capture, we suggest a real-time extrapolation algorithm. The realization of this prediction algorithm does not need statistical data or rely on an underlying cinematic human model with pre-defined marker distances. Under the assumption that natural motion can be linear, circular, or a linear combination of both, a prediction method is suggested and realized. The paper presents linear and circular movement measurements for use when a marker is briefly lost. The suggested extrapolation method seems to behave well for a reasonable number of frames, not exceeding 200 milliseconds.
2010 International Conference on Cyberworlds, 2010
On interactive surfaces, a precise calibration of the tracking system is necessary for an exact u... more On interactive surfaces, a precise calibration of the tracking system is necessary for an exact user interaction. So far, common calibration techniques focus on eliminating geometric distortions. This static calibration is only correct for a specific viewpoint of one single user and parallax error distortions still occur if this changes (i.e. if the user moves in front of the digital screen). In order to overcome this problem, we present an empirical model of the user's position and movement in front of a digital screen. With this, a model predictive controller is able to correct the parallax error for future positions of the user. We deduce the model's parameters from a user study on a large interactive whiteboard, in which we measured the 3D position of the user's viewpoint during common interaction tasks
We present InfrActables, a wireless technology for human computer interaction devices. It allows ... more We present InfrActables, a wireless technology for human computer interaction devices. It allows multiple users to interact simultaneously on back-projection displays. It recognizes each device’s position, orientation, and identification, but also enables the tools to communicate their states to the application that the user interacts with. This makes it possible to build complex interaction devices for direct manipulation with buttons, sliders, and other input capabilities. The technology was developed for a computer-supported environment, allowing multiple users to interact simultaneously on a surface using multiple styli and other user input devices. The principle of operation is not limited to two-dimensional surfaces, three-dimensional user input devices can also profit from its advantages.
Smart Structures and Materials 1999: Smart Structures and Integrated Systems, Mar 1999
Haptic rendering is the process of computing and generating forces in response to user interactio... more Haptic rendering is the process of computing and generating forces in response to user interactions with virtual objects. The interaction modality of haptic feedback gains more and more of importance for simulation tasks in virtual environments. However there are only very few portable haptic interfaces, with which the user can experience in a natural way the sensation of force feedback. The scope of this paper is to present a new portable haptic interface using shape memory alloy wires as actuators. Shape memory alloys (SMA), and especially the nickel-titanium compositions, offer a number of engineering properties available in no other material. The ability to respond with significant force and motion to small changes in ambient temperature and the capability to convert heat energy into mechanical work provide the designer with a new array of possibilities. Beside some application specific characterization of the actuator material with respect to energy consumption and dynamic behavior for loading, the mechanical layout of the interface is discussed in detail. To realize a light and compact design of the interface, a flexure hinge is considered as an essential part of interface.
In a collaborative environment, non-verbal communication elements carry important contents. These... more In a collaborative environment, non-verbal communication elements carry important contents. These contents are partially or completely lost in remote collaboration. This paper presents a system to address this issue by tracking pointing gestures, the main non-verbal communication element prevalent in such meetings. The setup employs a touchscreen tabletop computer system for representing the visual content of the meeting, together with three motion trackers for tracking the pointing gestures.
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In this paper, we describe an approach to apply Partially Observable Markov Decision Processes (POMDPs) for automatic online re-calibration to cope with changing viewpoints, which are indicated by uncertain observations of the user’s interaction quality on the surface.
In this paper, we describe an approach to apply Partially Observable Markov Decision Processes (POMDPs) for automatic online re-calibration to cope with changing viewpoints, which are indicated by uncertain observations of the user’s interaction quality on the surface.