The NavChair Assistive Wheelchair Navigation System
01 Dec 1999-Vol. 7, Iss: 4, pp 443-451
TL;DR: The NavChair Assistive Wheelchair Navigation System is being developed to reduce the cognitive and physical requirements of operating a power wheelchair for people with wide ranging impairments that limit their access to powered mobility.
Abstract: The NavChair Assistive Wheelchair Navigation System is being developed to reduce the cognitive and physical requirements of operating a power wheelchair for people with wide ranging impairments that limit their access to powered mobility. The NavChair is based on a commercial wheelchair system with the addition of a DOS-based computer system, ultrasonic sensors, and an interface module interposed between the joystick and power module of the wheelchair. The obstacle avoidance routines used by the NavChair in conjunction with the ultrasonic sensors are modifications of methods originally used in mobile robotics research. The NavChair currently employs three operating modes: general obstacle avoidance, door passage, and automatic wall following. Results from performance testing of these three operating modes demonstrate their functionality. In additional to advancing the technology of smart wheelchairs, the NavChair has application to the development and testing of "shared control" systems where a human and machine share control of a system and the machine can automatically adapt to human behaviors.
Citations
More filters
TL;DR: This paper focuses on the prospect of improving the lives of countless disabled individuals through a combination of BCI technology with existing assistive technologies (AT) and identifies four application areas where disabled individuals could greatly benefit from advancements inBCI technology, namely, “Communication and Control”, ‘Motor Substitution’, ”Entertainment” and “Motor Recovery”.
Abstract: In recent years, new research has brought the field of electroencephalogram (EEG)-based brain–computer interfacing (BCI) out of its infancy and into a phase of relative maturity through many demonstrated prototypes such as brain-controlled wheelchairs, keyboards, and computer games. With this proof-of-concept phase in the past, the time is now ripe to focus on the development of practical BCI technologies that can be brought out of the lab and into real-world applications. In particular, we focus on the prospect of improving the lives of countless disabled individuals through a combination of BCI technology with existing assistive technologies (AT). In pursuit of more practical BCIs for use outside of the lab, in this paper, we identify four application areas where disabled individuals could greatly benefit from advancements in BCI technology, namely, “Communication and Control”, “Motor Substitution”, “Entertainment”, and “Motor Recovery”. We review the current state of the art and possible future developments, while discussing the main research issues in these four areas. In particular, we expect the most progress in the development of technologies such as hybrid BCI architectures, user–machine adaptation algorithms, the exploitation of users’ mental states for BCI reliability and confidence measures, the incorporation of principles in human–computer interaction (HCI) to improve BCI usability, and the development of novel BCI technology including better EEG devices.
792 citations
Cites background from "The NavChair Assistive Wheelchair N..."
...The NavChair [104, 177] and the Bremen Autonomous Wheelchair [159] are examples of this second category....
[...]
TL;DR: New technologies that incorporate artificial intelligence techniques to support older adults and help them cope with the changes of aging, in particular with cognitive decline are surveyed.
Abstract: Today, approximately 10 percent of the world's population is over the age of 60; by 2050 this proportion will have more than doubled. Moreover, the greatest rate of increase is amongst the "oldest old," people aged 85 and over. While many older adults remain healthy and productive, overall this segment of the population is subject to physical and cognitive impairment at higher rates than younger people. This article surveys new technologies that incorporate artificial intelligence techniques to support older adults and help them cope with the changes of aging, in particular with cognitive decline.
532 citations
Cites background from "The NavChair Assistive Wheelchair N..."
...In addition, significant research has been done to design obstacleavoiding wheelchairs (see, for example, Yanco [2001] or Levine et al. [1999] )....
[...]
...In addition, significant research has been done to design obstacle-avoiding wheelchairs (e.g., [Yanco2001, Levine et al.1999])....
[...]
...[Levine et al.1999] Levine, S. P.; Bell, D. A.; Jaros, L. A.; Simpson, R. C.; Koren, Y.; and Borenstein, J. 1999....
[...]
TL;DR: Smart wheelchairs have been the subject of research since the early 1980s and have been developed on four continents and presented a summary of the current state of the art and directions for future research.
Abstract: — Several studies have shown that both children andadults benefit substantially from access to a means of indepen-dent mobility. While the needs of many individuals with disabil-ities can be satisfied with traditional manual or poweredwheelchairs, a segment of the disabled community finds it diffi-cult or impossible to use wheelchairs independently. To accom-modate this population, researchers have used technologiesoriginally developed for mobile robots to create “smart wheel-chairs.” Smart wheelchairs have been the subject of researchsince the early 1980s and have been developed on four conti-nents. This article presents a summary of the current state of theart and directions for future research. Key words: artificial intelligence, independent mobility, infra-red range finder, laser range finder, machine vision, powerwheelchairs, robotics, sonar, subsumption, voice control. INTRODUCTION Several studies have shown that both children andadults benefit substantially from access to a means ofindependent mobility, including power wheelchairs, man-ual wheelchairs, scooters, a nd walkers [1–2]. Independentmobility increases vocational and educational opportuni-ties, reduces dependence on caregivers and family mem-bers, and promotes feelings of self-reliance. For youngchildren, independent mobility serves as the foundationfor much early learning [1]. Nonambulatory children lackaccess to the wealth of stimuli afforded self-ambulatingchildren. This lack of exploration and control often pro-duces a cycle of deprivation and reduced motivation thatleads to learned helplessness [3].For adults, independent mobility is an importantaspect of self-esteem and plays a pivotal role in “aging inplace.” For example, if older people find it increasinglydifficult to walk or wheel themselves to the commode,they may do so less often or they may drink less fluid toreduce the frequency of urination. If they become unableto walk or wheel themselves to the commode and help isnot routinely available in the home when needed, a moveto a more enabling environment (e.g., assisted living) maybe necessary. Mobility limitati ons are the leading cause offunctional limitations among adults, with an estimatedprevalence of 40 per 1,000 persons age 18 to 44 and 188per 1,000 at age 85 and older [4]. Mobility difficulties arealso strong predictors of activities of daily living (ADL)and instrumental ADL disabi lities because of the need to
531 citations
01 Mar 2001
TL;DR: The GuideCane is a device designed to help blind or visually impaired users navigate safely and quickly among obstacles and other hazards with a very noticeable force felt in the handle.
Abstract: The GuideCane is a device designed to help blind or visually impaired users navigate safely and quickly among obstacles and other hazards. During operation, the user pushes the lightweight GuideCane forward. When the GuideCane's ultrasonic sensors detect an obstacle, the embedded computer determines a suitable direction of motion that steers the GuideCane and the user around it. The steering action results in a very noticeable force felt in the handle, which easily guides the user without any conscious effort on his/her part.
397 citations
10 May 2010
TL;DR: The brain controlled wheelchair (BCW) described in this paper enabled the users to move to various locations in less time and with significantly less control effort than other control strategies proposed in the literature.
Abstract: While brain-computer interfaces (BCIs) can provide communication to people who are locked-in, they suffer from a very low information transfer rate. Further, using a BCI requires a concentration effort and using it continuously can be tiring. The brain controlled wheelchair (BCW) described in this paper aims at providing mobility to BCI users despite these limitations, in a safe and efficient way. Using a slow but reliable P300 based BCI, the user selects a destination amongst a list of predefined locations. While the wheelchair moves on virtual guiding paths ensuring smooth, safe, and predictable trajectories, the user can stop the wheelchair by using a faster BCI. Experiments with nondisabled subjects demonstrated the efficiency of this strategy. Brain control was not affected when the wheelchair was in motion, and the BCW enabled the users to move to various locations in less time and with significantly less control effort than other control strategies proposed in the literature.
371 citations
Cites background from "The NavChair Assistive Wheelchair N..."
...Moreover, autonomous vehicles have been observed to refuse to move forward due to some obstacles, while a human driver would easily be able to move its way through [8]....
[...]
References
More filters
Book•
01 Jun 1991TL;DR: A new architecture for controlling mobile robots is described, building a robust and flexible robot control system that has been used to control a mobile robot wandering around unconstrained laboratory areas and computer machine rooms.
Abstract: A new architecture for controlling mobile robots is described. Layers of control system are built to let the robot operate at increasing levels of competence. Layers are made up of asynchronous modules that communicate over low-bandwidth channels. Each module is an instance of a fairly simple computational machine. Higher-level layers can subsume the roles of lower levels by suppressing their outputs. However, lower levels continue to function as higher levels are added. The result is a robust and flexible robot control system. The system has been used to control a mobile robot wandering around unconstrained laboratory areas and computer machine rooms. Eventually it is intended to control a robot that wanders the office areas of our laboratory, building maps of its surroundings using an onboard arm to perform simple tasks.
7,759 citations
"The NavChair Assistive Wheelchair N..." refers background in this paper
...The Wheelesly and TAO [13] smart wheelchairs are examples of subsumption-based systems [11] originally developed by Brooks....
[...]
01 Mar 1986
TL;DR: In this paper, a new architecture for controlling mobile robots is described, which is made up of asynchronous modules that communicate over low-bandwidth channels, each module is an instance of a fairly simple computational machine.
Abstract: A new architecture for controlling mobile robots is described. Layers of control system are built to let the robot operate at increasing levels of competence. Layers are made up of asynchronous modules that communicate over low-bandwidth channels. Each module is an instance of a fairly simple computational machine. Higher-level layers can subsume the roles of lower levels by suppressing their outputs. However, lower levels continue to function as higher levels are added. The result is a robust and flexible robot control system. The system has been used to control a mobile robot wandering around unconstrained laboratory areas and computer machine rooms. Eventually it is intended to control a robot that wanders the office areas of our laboratory, building maps of its surroundings using an onboard arm to perform simple tasks.
7,291 citations
01 Jan 1991
TL;DR: A real-time obstacle avoidance method for mobile robots which has been developed and implemented, named the vector field histogram (VFH), permits the detection of unknown obstacles and avoids collisions while simultaneously steering the mobile robot toward the target.
Abstract: A real-time obstacle avoidance method for mobile robots which has been developed and implemented is described. This method, named the vector field histogram (VFH), permits the detection of unknown obstacles and avoids collisions while simultaneously steering the mobile robot toward the target. The VFH method uses a two-dimensional Cartesian histogram grid as a world model. This world model is updated continuously with range data sampled by onboard range sensors. The VFH method subsequently uses a two-stage data-reduction process to compute the desired control commands for the vehicle. Experimental results from a mobile robot traversing densely cluttered obstacle courses in smooth and continuous motion and at an average speed of 0.6-0.7 m/s are shown. A comparison of the VFN method to earlier methods is given. >
2,352 citations
01 Jan 1989
TL;DR: A real-time obstacle avoidance approach for mobile robots that permits the detection of unknown obstacles simultaneously with the steering of the mobile robot to avoid collisions and advance toward the target.
Abstract: A real-time obstacle avoidance approach for mobile robots has been developed and implemented. It permits the detection of unknown obstacles simultaneously with the steering of the mobile robot to avoid collisions and advance toward the target. The novelty of this approach, entitled the virtual force field method, lies in the integration of two known concepts: certainty grids for obstacle representation and potential fields for navigation. This combination is especially suitable for the accommodation of inaccurate sensor data as well as for sensor fusion and makes possible continuous motion of the robot with stopping in front of obstacles. This navigation algorithm also takes into account the dynamic behavior of a fast mobile robot and solves the local minimum trap problem. Experimental results from a mobile robot running at a maximum speed of 0.78 m/s demonstrate the power of the algorithm. >
1,171 citations
01 Jan 1991
TL;DR: HIMM has been implemented and tested on a mobile robot and its dual functionality was demonstrated through numerous tests in which maps of unknown obstacle courses were created, while the robot simultaneously performed real-time obstacle avoidance maneuvers at speeds of up to 0.78 m/s.
Abstract: Histogramic in-motion mapping (HIMM) is introduced as a new method for real-time map building with a mobile robot motion. HIMM represents data in a two-dimensional array, called a histogram grid, that is updated through rapid in-motion sampling of on-board range sensors. Rapid in-motion sampling results in a map representation that is well-suited to modeling inaccurate and noisy range-sensor data, such as those produced by ultrasonic sensors, and requires minimal computational overhead. Fast map building allows the robot to use immediately the mapped information in real-time obstacle-avoidance algorithms. The benefits of this integrated approach are quick, accurate mapping and safe navigation of the robot toward a given target. HIMM has been implemented and tested on a mobile robot. Its dual functionality was demonstrated through numerous tests in which maps of unknown obstacle courses were created, while the robot simultaneously performed real-time obstacle avoidance maneuvers at speeds of up to 0.78 m/s. >
449 citations