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| United States Patent Application |
20080174451
|
| Kind Code
|
A1
|
|
Harrington; Nathan J.
; et al.
|
July 24, 2008
|
METHOD AND SYSTEM FOR IMPROVING DRIVER SAFETY AND SITUATIONAL AWARENESS
Abstract
A method for enhancing driver safety through body position monitoring with
remote sensors, and furnishing feedback in response to vehicle motion,
driver activities, and external driving conditions, wherein the method
includes: monitoring and characterizing signals from at least one sensor
mounted on the body of a driver; monitoring and characterizing signals
from at least one vehicle mounted sensor; determining driver activity
based on disambiguating the signals from the driver and vehicle mounted
sensors; providing feedback to the driver based on the determined driver
activity, vehicle motion, and external driving conditions; and wherein
the feedback is employed to modify driver behavior and enhance driver
safety.
| Inventors: |
Harrington; Nathan J.; (Cary, NC)
; Narayanaswami; Chandrasekhar; (Wilton, CT)
|
| Correspondence Name and Address:
|
CANTOR COLBURN LLP-IBM YORKTOWN
20 Church Street, 22nd Floor
Hartford
CT
06103
US
|
| Assignee Name and Adress: |
INTERNATIONAL BUSINESS MACHINES CORPORATION
Armonk
NY
|
| Serial No.:
|
626097 |
| Series Code:
|
11
|
| Filed:
|
January 23, 2007 |
| U.S. Current Class: |
340/905 |
| U.S. Class at Publication: |
340/905 |
| Intern'l Class: |
G08G 1/09 20060101 G08G001/09 |
Claims
1. A method for enhancing driver safety through body part position
monitoring with remote sensors, and furnishing feedback in response to
vehicle motion, driver activities, and external driving conditions,
wherein the method comprises:monitoring signals from at least one sensor
mounted on a body part of a driver;monitoring signals from at least one
vehicle mounted sensor;determining driver activity based on the signals
from the driver and vehicle mounted sensors; andproviding feedback to the
driver based on the determined driver activity, vehicle motion, and
external driving conditions.
2. The method of claim 1, wherein:the determining of driver activity is
based on correlating accelerometer data from a sensor mounted on a upper
limb of the driver with corresponding driver steering wheel control
actions.
3. The method of claim 1, wherein:the providing of feedback to the driver
is vibro-tactile feedback having a specified pattern and duration;
andwherein the provided feedback alerts the driver without the knowledge
of passengers in the vehicle.
4. The method of claim 3, wherein:the duration of the vibro-tactile
feedback is based on a stress level that the driver is experiencing as a
result of the driving activity, vehicle motion, and external driving
conditions.
5. The method of claim 3, wherein:the duration of the vibro-tactile
feedback is about 3 seconds based on a high stress level activity.
6. The method of claim 3, wherein:the pattern of the vibro-tactile
feedback is based on a stress level that the driver is experiencing as a
result of the driving activity, vehicle motion, and external driving
conditions.
7. The method of claim 1, wherein:the providing of feedback to the driver
is directly applied to the part of the driver's body requiring behavior
modification.
8. The method of claim 1, wherein:the providing of vibro-tactile feedback
to the driver is through a wrist mounted device.
9. A system for enhancing driver safety through body part position
monitoring with remote sensors, and furnishing feedback in response to
vehicle motion, driver activities, and external driving conditions, the
system comprising:a network of sensors including at least one sensor
mounted on a body part of the driver, and at least one vehicle mounted
sensor;a computing device in electrical signal communication with a
network of sensors;wherein the computing device is configured to execute
electronic software that manages the network of sensors;wherein the
electronic software is resident on a storage medium in signal
communication with the computing device; andwherein the electronic
software determines driver activity based on the signals from the driver
and vehicle mounted sensors, and provides feedback to the driver based on
the determined driver activity, vehicle motion, and external driving
conditions; andwherein the feedback is employed to modify driver behavior
and enhance driver safety.
10. The system of claim 9, wherein:the determining of driver activity is
based on correlating accelerometer data from the sensor mounted on an
upper limb of the driver with corresponding driver steeling wheel control
actions.
11. The system of claim 9, wherein:the providing of feedback to the driver
is vibro-tactile feedback having a specified pattern and duration.
12. The system of claim 11, wherein:the duration of the vibro-tactile
feedback is based on a stress level that the driver is experiencing as a
result of the driving activity, vehicle motion, and external driving
conditions; andwherein the duration of the vibro-tactile feedback is
inversely proportional to the stress level.
13. The system of claim 11, wherein:the pattern of the vibro-tactile
feedback is based on a stress level that the driver is experiencing as a
result of the driving activity, vehicle motion, and external driving
conditions.
14. The system of claim 9, wherein:the vehicle mounted sensors are
embedded in a steering wheel; andwherein the embedded sensors within the
steering wheel further comprise:pressure sensitive switches; andwherein
the pressure sensitive switches can detect when the driver has their
hands on the wheel, or if the drivers hands are in a non-optimal
position.
15. The system of claim 9, wherein:the providing of feedback to the driver
is directly applied to the past of the driver's body requiring behavior
modification.
16. The system of claim 9, wherein:the providing of vibro-tactile feedback
to the driver is through a wrist mounted device.
17. The system of claim 9, wherein:the sensor is mounted on the upper limb
of a driver and employs Radio Frequency Identification (RFID) tags and
readers embedded in a vehicle's steering wheel to determine the proximity
of the drivers hands to the vehicle's steering wheel.
18. The system of claim 9, wherein:the sensor is mounted on the tipper
limb of a driver and employs Bluetooth transmission and receivers
embedded in a vehicle's steering wheel to determine the proximity of the
driver's hands to the vehicle's steeling wheel.
19. An article comprising machine-readable storage media containing
instructions that when executed by a processor enable the processor to
manage a system for enhancing driver safety through body part position
and vehicle monitoring with remote sensors in electrical communication
with a computing device, and furnishing feedback in response to vehicle
motion, driver activities, and external driving conditions, wherein the
instructions comprise:monitoring signals from at least one sensor mounted
on a body part of a driver;monitoring signals from at least one vehicle
mounted sensor;determining driver activity based on the signals from the
driver and vehicle mounted sensors; andproviding feedback to the driver
based on the determined driver activity, vehicle motion, and external
driving conditions.
20. The article of claim 19, wherein:the instructions, in response to
correlating accelerometer data from a sensor mounted on the upper limb of
the driver with corresponding driver steering wheel control actions
provides vibro-tactile feedback to the driver having a specified pattern
and duration; andthe pattern and duration of the vibro-tactile feedback
is based on a stress level that the driver is experiencing as a result of
the driving activity, vehicle motion, and external driving conditions.
Description
TRADEMARKS
[0001]IBM.RTM. is a registered trademark of International Business
Machines Corporation, Armonk, N.Y., U.S.A. Other names used herein may be
registered trademarks, trademarks or product names of International
Business Machines Corporation or other companies.
BACKGROUND OF THE INVENTION
[0002]1. Field of the Invention
[0003]This invention relates generally to electronic monitoring and
real-time safety feedback and behavior modification, and more
particularly to providing a method, auricle, and system for enhancing
driver safety through body position monitoring with remote sensors, and
furnishing feedback in response to vehicle motion, driver activities, and
external driving conditions.
[0004]2. Description of the Related Art
[0005]Advancements in vehicle safety have progressed over the years, with
new safety features and enhancements introduced with successive
generations of vehicles. Safety features have evolved either by
government mandate, or market driven demand. Early safety features
included radial tires, padded dashboards, safety glass, and passive
restraints (seat belts). The current generation of vehicles comes
equipped with a myriad of safety features including front and side
airbags, antilock brakes, vehicular steering assist, lane departure
warning, collision avoidance systems, nm flat tires, night vision
systems, etc. The present day safety features rely on onboard vehicle
equipped sensors and computers to monitor environmental, road, and
vehicle conditions and parameters, as well as to provide feedback to the
key vehicle safety and control systems. However, the feedback and control
systems do little to monitor driver behavior.
[0006]Previous work with "lightweight" wearable computing technology for
activity detection required the use of bulky hardware and physical
modification of objects for recognition. Video processing, physiological
monitoring devices, and other "heavyweight" sensors have had success in
determining stress levels of a general user and broad context activities.
Consumer level wearable computers, such as Personal Digital Assistants
and upcoming cellular phones, can provide integrated accelerometer
sensors for activity detection based on the kinematics of the human body
as a whole. However, these consumer level wearable computers have limited
utility in a vehicle environment, as the driver is in a seated position,
and the accelerometer readings would not be able to distinguish driver
from passenger activities unless mounted on an upper limb.
[0007]Recent efforts with ubiquitous and wearable sensors in the vehicular
context have demonstrated the value of multi-sensory inputs to the driver
to enhance situational awareness. Studies using vibro-tactile stimulators
on the driver's torso have decreased the response time to critical events
in simulations, and at least one car company has deployed a vibro-tactile
warning system for unexpected lane departure. Additional research has
created environmental and navigational control interfaces that
significantly enhance the time drivers spend with their eyes and
attention focused on the road, instead of the control interface.
Vibro-tactile feedback mechanisms to both traffic-related and
control-activation information have been shown to be highly beneficial in
the vehicular context due to its low impact on the driver's analytical
processes, while retaining the ability to be easily integrated into the
driver's task workload. Vibro-tactile feedback can also be delivered
privately compared to audio or graphical means. Work has been conducted
with piezo-electric sensors and motors to provide haptic feedback on
mobile computing/communication devices to facilitate vision free
interaction. It has been found that users are able to distinguish between
several "tactons"-tactile icons. However, these test to determine how
many patterns a user is able to detect have been conducted under ideal
conditions where the user is stationary and mainly focusing on haptic
pattern detection, and not on a primary activity such as driving in a
moving vehicle.
SUMMARY OF THE INVENTION
[0008]Embodiments of the present invention include a method for enhancing
driver safety through body position monitoring with remote sensors, and
furnishing feedback in response to vehicle motion, driver activities, and
external driving conditions, wherein the method includes: monitoring and
characterizing signals from at least one sensor mounted on the body of a
driver; monitoring and characterizing signals from at least one vehicle
mounted sensor; determining driver activity based on disambiguating the
signals from the driver and vehicle mounted sensors; providing feedback
to the driver based on the determined driver activity, vehicle motion,
and external driving conditions; and wherein the feedback is employed to
modify driver behavior and enhance driver safety.
[0009]A system for enhancing driver safety through body position
monitoring with remote sensors, and furnishing feedback in response to
vehicle motion, driver activities, and external driving conditions,
wherein the system includes a computing device in electrical signal
communication with a network of sensors; wherein the network of sensors
include: at least one sensor mounted on the body of a driver; at least
one vehicle mounted sensor; and wherein the computing device is
configured to execute electronic software that manages the network of
sensors; wherein the electronic software is resident on a storage medium
in signal communication with the computing device; and wherein the
electronic software determines driver activity based on disambiguating
the signals from the driver and vehicle mounted sensors, and provides
feedback to the driver based on the determined driver activity, vehicle
motion, and external driving conditions; and wherein the feedback is
employed to modify driver behavior and enhance driver safety.
[0010]An article including machine-readable storage media containing
instructions that when executed by a processor enable the processor to
manage a system for enhancing driver safety through body position
monitoring with remote sensors, and furnishing feedback in response to
vehicle motion, driver activities, and external driving conditions,
wherein the system includes a computing device in electrical signal
communication with a network of sensors; and wherein the network of
sensors includes: at least one sensor mounted on the body of a driver; at
least one vehicle mounted sensor; and wherein the computing device is
configured to execute electronic software containing the instructions
that manage the network of sensors; wherein the electronic software is
resident on a storage medium in signal communication with the computing
device; and wherein the electronic software determines driver activity
based on disambiguating the signals from the driver and vehicle mounted
sensors, and provides feedback to the driver based on the determined
driver activity, vehicle motion, and external driving conditions; and
wherein the feedback is employed to modify driver behavior and enhance
driver safety.
[0011]Additional features and advantages are realized through the
techniques of the present invention. Other embodiments and aspects of the
invention are described in detail herein and are considered a part of the
claimed invention. For a better understanding of the invention with
advantages and features, refer to the description and to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012]The subject matter that is regarded as the invention is particularly
pointed out and distinctly claimed in the claims at the conclusion of the
specification. The foregoing and other objects, features, and advantages
of the invention are apparent from the following detailed description
taken in conjunction with the accompanying drawings in which:
[0013]FIG. 1 is a pictorial representation of the wrist mount
vibro-tactile feedback mechanism in the form of IBM's WatchPad according
to an embodiment of the invention.
[0014]FIG. 2 illustrates typical accelerometer data acquired from the
wrist mounted vibro-tactile feedback mechanism and vehicle sensors
according to an embodiment of the invention.
[0015]FIG. 3 is a block diagram of the major system components employed in
embodiments of the invention.
[0016]The detailed description explains the preferred embodiments of the
invention, together with advantages and features, by way of example with
reference to the drawings.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
[0017]Embodiments of the present invention provide a method, article, and
system for enhancing driver safety through body position monitoring with
remote sensors in response to vehicle motion, driver activities, and
external driving conditions. Embodiments of the present invention outfit
drivers with wearable sensors and computers for the purpose of monitoring
driver behavior and inducing behavior modification. An embodiment of the
present invention exploits the sensory input recognition threshold of
drivers responding to wrist-located vibro-tactile events, and employs an
algorithm for detecting whether a driver has their hand on the steeling
wheel. Road tests with several drivers subjected to varying road
conditions (including stressful driving conditions) are used to create a
model for required duration for event notification based upon real-time
vehicle dynamics. One embodiment of the present invention provides driver
behavior modification during stressful driving conditions utilizing a
wrist mounted vibro-tactile feedback mechanism (for example, IBM's
WatchPad) and vehicle mounted accelerometer sensor data. Additional
embodiments of the present invention can monitor if the driver is holding
the steeling wheel correctly, if their drowsy, eating while driving,
holding a cell phone, and either warning the user or changing vehicle
system parameters to compensate. The safety features of the present
invention can be incorporated into newly sold cars, or sold as after
market equipment by insurance companies, for example.
[0018]Recent advances in miniaturization of spatial orientation sensors,
wireless networking, and platform integration have created a new class of
wearable computers. These advanced systems are differentiated from
experimental and domain-specific wearable computers by their unobtrusive
physical dimensions and availability as consumer grade devices. The IBM
WatchPad is an example of a wearable computer in the sense that it does
not get in the way of everyday life, and yet still provides a robust
computing platform running a full operating system and sensor suite. As
previously stated, an embodiment of the present invention integrates the
WatchPad into the vehicle's sensory input environment, thereby increasing
situational awareness and enhancing the safety of the driving process.
Information about the sensory input recognition threshold of
vibro-tactile events on the driver's wrist via the WatchPad is utilized
as a feedback mechanism that takes advantage of the drivers ability to
determine with a coarse resolution vibratory events while operating a
vehicle under real-world driving conditions, and consistently integrating
the processing the vibro-tactile events into their task hierarchy.
[0019]A first embodiment of the present invention combines activity
detection of the upper limb wearable device with in-vehicle sensors to
detect the current activity of the driver's wrist, and modifies the
driving behavior based on that activity, by determining the mean
temporal-duration and temporal-pattern resolution of wrist located
vibro-tactile events during various levels of driving-related stress. An
algorithm is employed to determine wrist activity with enhanced
disambiguation using vehicle attached onboard sensor data. Based on the
algorithm, a notification model to reliably notify the driver of critical
events through the vibro-tactile interface without triggering a startle
reflex or causing inattentiveness to critical driving activities.
[0020]The wrist-mounted device of an embodiment of the present invention
is capable of sensing the position of the driver's wrist and also
provides vibro-tactile feedback. An example of a wrist-mounted device
used in developing an embodiment of the present invention is the
aforementioned IBM WatchPad 100 that is depicted in FIG. 1. The WatchPad
provides vibro-tactile feedback and also acts as an accelerometer data
collection sensor with a small form factor and onboard processing
capabilities. The WatchPad runs on a Linux kernel and employs Bluetooth
wireless communication, and incorporates vibrational motors to provide
the vibro-tactile feedback.
[0021]Table 1 lists twelve monitored driving activities used for data
collection to establish the operational parameters of the first
embodiment of the present invention. The monitored activities were common
driving tasks associated with real-world activities, and were performed
in suburban and rural environments. All data collection runs were
performed during daylight conditions with normal traffic flow and weather
conditions. To conduct the driving, five drivers of widely varying
experience levels, genders, and familiarity with wearable computing
devices were selected. The mean length of driver experience was 12.8
years, and their mean age was 32.4 years. Participants were given a basic
description of the experimental process and were instructed to describe
the duration and temporal-pattern characteristics of the vibro-tactile
input to their wrist while driving. The mean duration of the data
collection runs was 18.2 minutes. A laptop computer equipped with
accelerometers was mated with the vehicles chassis to record roll and
pitch movements of the vehicle independent of the wrist mounted
monitoring device. The accelerometer measurements from the laptop were
used to providing disambiguation of the wrist mounted (WatchPad)
accelerometer data during the signal analysis phase.
TABLE-US-00001
TABLE 1
Activity Description
1 Parking Lot Navigation
2 Pulling into parking space
3 Pulling out of parking space
4 Left turn across traffic
5 Right turn with no stop
6 Straight line acceleration
7 Merging onto highway
8 Braking for stoplight
9 Braking for stop sign
10 Backing out of a parking space
11 Backing into a parking space
12 Driving on gravel road
[0022]During the data acquisition phase the drivers wore the WatchPad on
the right or left wrist (depending on their preference), while the laptop
computer recorded real-time 5 Hz telemetry from the WatchPad bi-axial
accelerometer data (see FIG. 2). Measurements of the vehicle's roll and
pitch were recorded at 10 Hz on the accelerometers in the laptop (see
FIG. 2). After a brief demonstration to the driver of the type of
vibration to expect, the experimenter (a co-passenger in the test
vehicle) began data collection runs, and supplied simple navigational
instructions during the run. During various points in the data collection
runs, vibro-tactile events of specific temporal-duration and
temporal-patterns were sent to the driver's wrist mounted device, with
the driver providing verbal feedback on the type of event sensed. For
example, during a driving activity listed in Table 1, the experimenter
would send a temporal-pattern event (two quick buzzes, for example) to
the driver's WatchPad from the onboard laptop. The controlling laptop
recorded the time the temporal-pattern event was sent, and the
experimenter recorded the driver's response rate when the driver
responded with a description of the event they sensed. The driver
response rate is the elapsed time between when the temporal-pattern event
signal was sent and when the driver responded. The laptop also provided
accelerometer trending data and three-dimensional representations of the
orientation of the WatchPad and laptop that provided in situ tools for
annotation and variability monitoring for analysis. Secondary sensor
integration is also possible with onboard vehicle hardware, or with other
wearable computers the driver might have. For example, some personal
digital assistants (PDA) come equipped with accelerometers that can
measure the characteristic motion of a vehicle from the wear's pocket,
and provide disambiguation data to the WatchPad. In addition, a video
camera was used to capture the exchanges between the drivers and
experimenter for analysis. The video of the driving process, the
time-coded annotation of events, and subsequent driver responses were
recorded. Playback and analysis of experimental runs were performed at
various rates to determine what characteristics of the accelerometer data
indicated a driving condition, and what types of vibro-tactile events the
drivers under differing levels of stress detected. The annotation and
video recording of the data collection runs was critical in correlating
what signals can be expected from the wrist mounted WatchPad while the
drivers had their hands on the vehicle steering wheel. Additionally, the
video recording and environmental factors annotation were critical in
examining the variability related to vibro-tactile sensory threshold due
to stressful driving conditions. The data collected during the
experimentation process provided the following unique parameters:
[0023]Real-world data collection of the spatial orientation of the
driver's wrist during unpredictable driving events. [0024]Impact on
driver workload of wrist mounted vibro-tactile events.
[0025]Temporal-pattern resolution threshold of wrist-located
vibro-tactile events during stressful driving activities.
[0026]Previous work related to vibro-tactile feedback has shown that
drivers readily recognize vabro-tactile events of sufficient temporal
duration. Peripheral vision detection tasks, such as monitoring
informational readout displays on the vehicle dashboard are more
difficult to detect, or require increased persistence to ensure driver
detection. Visual and audible alerts in the automotive context can be
difficult to detect for drivers with decreased visual and audio sensory
capabilities. Research has shown that while many drivers have decreased
vision and hearing capabilities with age, their sense of touch continues
relatively unchanged throughout life. The data collected during the
experimentation process in the development of the first embodiment of the
present invention showed that although the wrist located vibro-tactile
events were consistently detected, their temporal-pattern characteristic
determination is heavily impacted by specific driver activity. In
addition, the cognitive ability of the user to continue driving
activities while reporting on the characteristics of the current
vibration event is also heavily dependent on current stress levels.
[0027]While performing straight-line driving tasks at low or high speed
(such as driving activities 6, 8, 9 or 12 from Table 1), drivers were
able to almost immediately describe the temporal-duration and
temporal-pattern characteristics of the vibration events received through
the WatchPad. For example, the "straight line acceleration event"--number
6 from Table 1, had a mean approximate driver-notification response time
of 0.5 seconds, an approximate temporal-duration accuracy rating of 75%,
and an approximate temporal-pattern accuracy rating of 95%. During nearly
every straight line acceleration event, whether rural or suburban,
inexperienced driver or seasoned, the driver was capable of determining
quickly that a vibration event had occurred, its approximate duration,
and whether it was a multiple quick-vibration event, Average accuracy
ratings are used due to the variability of driver's internal timing
capabilities and estimates, and variability in the Watchpad's vibration
timing code.
[0028]Conversely, during stressful driving events, such as parking lot
maneuvering (activity 1, 2, 3, 10, and 11), or highway related events
(activity 7) driver recognition of nearly all vibro-tactile events from
the WatchPad is severely degraded. During parking lot maneuvering events,
mean approximate driver notification response time increased five fold to
2.5 seconds, approximate temporal-duration accuracy was 75%, and
approximate temporal-pattern accuracy was 5.6%
[0029]Activity 12 (Table 1)--driving on a gravel road--was included in the
experiment to help disambiguate steering wheel induced vibrations from
WatchPad vibro-tactile events. During testing, the low order vibrations
transmitted through the steering wheel were easily differentiated from
WatchPad vibrations even when driving over potholes and rough road
sections. There was no appreciable change from data collected during
driving on regular asphalt roads in any of the measured driver response
characteristics.
[0030]Of particular note is the loss of cognitive ability to reliably
determine multiple quick-vibration events during stressful driving
conditions. Although easily recognized during straight-line low-stress
activities, drivers only 5.6% of the time recognized a pause of 0.5
seconds between vibration events. In the remainder of the cases, the
driver described a single vibration event. Although the driver was unable
to rapidly describe the characteristics of the event received, and the
pause between vibration events was beyond the cognitive abilities of most
drivers under most circumstances, coarse recognition of the duration of
the vibration event was still reliably acquired.
[0031]A vibro-tactile event of duration greater than 3 seconds was
accurately recognized by drivers under all driving conditions, and forms
the basis of the notification system of the present invention.
Notification events under "maximum" stress will require a notification of
at a minimum 3 seconds, and lower stress events will have a
correspondingly shorter minimum duration of notification. This approach
allows for further intergration of non-critical events (such as
in-vehicle information system events) into the notification scheme.
[0032]Table 2 shows the weighted scale of stressfulness of selected
driving activities that were listed in Table 1.
TABLE-US-00002
TABLE 2
Activity Description Stressfulness
1 Parking lot navigation 2.5
2 Pulling into parking space 4.1
3 Pulling out of parking space 2.8
4 Left turn across traffic 5.2
7 Merging onto highway 5.7
10 Backing out of a parking space 4.4
11 Backing into a parking space 2.6
[0033]The values in the stress-indicator column of Table 2 are derived
from the following formula:
S=(.SIGMA.((evr.sub.i*evs.sub.i)/n)/(str.sub.j*sts.sub.j))
where evr is the driver description response rate for a straight line
driving activity; evs is the temporal pattern accuracy of the activity;
str is the response rate for the stressful driving activity; and sts is
the temporal-pattern accuracy for the stressful driving activity. The
stressfulness (S) of activity j, is determined by the average value for
all straight-line activities divided by the value for event j. Values of
S closer to one indicate a low-stress activity, and higher values
indicate a high-stress activity. Using this formula, the relative
stressfulness of any driving activity can be computed. Combining the
computed stressfulness with the acquisition of information about the
current wearer's (driver) activity and vehicle dynamics, a model can be
created for efficient notification of driver activity.
[0034]Time code annotated logs of the data collection runs provided a set
of time intervals with which the driver had their WatchPad-worn wrist
hand located on the steering wheel. In real-world driving, it was
discovered that 80% of the time the vehicle is under medium G load
acceleration, between 0.1 and 0.5 G, the driver's hand is on the steering
wheel. Medium G loads events include negotiating a highway on-ramp, cross
traffic turning, and gravel road driving, amongst others. Low G load
acceleration events of the vehicle, such as negotiating a parking lot, or
backing out of a driveway frequently show the driver's hand off the
steering wheel. The torso position of the driver while in reverse gear,
and the rapid steering wheel movements associated with these activities
frequently prevent the users hand from touching the steeling wheel for
significant time periods.
[0035]Conversely, the majority of driving activities involve low-level
steering wheel inputs on relatively straight paths in both suburban and
rural environments. For example, the wrist rarely moves more than 9
centimeters in the vertical dimension or 4 centimeters in the horizontal
while negotiating curves at highway speeds. Even with deflections from
center steering wheel position of 30 degrees, the acceleration measured
from the WatchPad vertical and horizontal accelerometers remains
relatively constant.
[0036]FIG. 2 illustrates data collected from wrist and vehicle mounted
accelerometers from a typical experimental run. In regions 210, 212, 222,
and 224 located near the beginning and end of the sampling timelines
(x-axis shows time in milliseconds) (202, 204, 206, 208) for recorded
movements in the x and y spatial domain (gX and gY, respectively), the
WatchPad accelerometers registered a high rate of wrist movement that can
be associated with a rapidly moving steering wheel that is characteristic
of parking lot maneuvers with low speed turns. Regions 214, 216, 218, and
220 represent the "Common Driving Signal" that refers to the most
frequently repeated characteristics of data measurement during
experimentation. Specifically, gX-axis (202) measurements of 24
centimeters, and gY-axis measurements (204) of 12 centimeters during the
various periods the driver had their hands upon the steering wheel.
Empirical observations show that a gX-axis measurement of 24 centimeters
roughly corresponds to a 31 degree angle of the driver's wrist, as
measured with a "zero" state being the driver's forearm parallel to the
earth's surface. A gY-axis measurement of 12 centimeters corresponds to a
14 degree angle of the driver's wrist when the driver's arm is held
perpendicular to the earth's surface as a "zero" state.
[0037]For the large data set of various driving routes, vehicles and
individuals, a broad time window was required to definitively determine
that the driver had their hand on the steering wheel. For any given time
window of 10 seconds, if the ratio of gX=.+-.24 cm and gY=.+-.12 cm to
gX.noteq..+-.24 cm and gY.noteq..+-.12 cm is greater than 40%, it can be
concluded that the diver is operating the steering wheel. The large time
window is necessary to compensate for control usage, such as turn signal
activation, or the driver scratching their face. The data derived during
the aforementioned experimentation process provides the capability to
recognize when the driver does not have their hand on the steering wheel
while the vehicle is in motion, as well as appropriate duration of
notifications required to ensure reliable communication of vibro-tactile
events.
[0038]Inattentiveness is a major factor in vehicle accidents, and while
the wrist mounted vibro-tactile feedback mechanism (IBM's WatchPad) is
not equipped to monitor cognitive inattentiveness, it can discern
secondary activities, which may indicate the driver is not satisfactorily
involved in the driving process. During the experimentation/data
acquisition phase, many drivers were observed placing their WatchPad
located arm down onto the armrest, especially on rural roads under
straight line driving conditions. While this activity is not necessarily
an indicator of decreased focus on the driving task, having both hands on
the wheel is the ideal driving condition. The WatchPad vibro-tactile
interface is well suited for informing the driver of their hand position,
as the closely coupled feedback mechanism will reduce the cognitive load
on the driver. Unlike audible alerts or visual cues to place their hand
back on the wheel, the vibration of the WatchPad is an alert mechanism
located directly on the physical appendage that needs to relocate. In
addition, vibro-tactile feedback can be private. Previous work in
vibro-tactile alert systems signal the driver to monitor other
information systems in the vehicle, whereas the model provided by
embodiments of the present invention facilitate direct physical behavior
altering cues for the driver, with minimal cognitive load. For example,
if the vehicle is in motion, and the driver's hand is not on the steering
wheel, a vibro-tactile alert of specific duration, where the duration is
based upon the stress-factor of the current driving activity, is
initiated. If the stressfulness of the current driving activity is
greater than the minimum threshold, a vibro-tactile alert of about 3
seconds in duration is sent to the wrist mounted WatchPad vibro-tactile
interface.
[0039]Exceptions are made if the driver's hand is not on the wheel for
parking lot events. Due to factors requiring extreme wrist motion away
from the wheel during normal parking lot activities, if the onboard
accelerometer is indicating low-speed g-force events, then the
vibro-tactile alerts will not be sent. Critical vehicle informational
events (such as brake failure) can still be sent to the WatchPad with a
duration appropriate to the stressfulness of the parking lot navigation
activity. For some types of messages, a buzz on the wrist may be employed
to draw the driver's attention to a larger display, such as the
dashboard, or projected on the windshield.
[0040]Additional embodiments of the present invention can tale into
account the driver's position of holding the steering wheel. While the
most recommended position to hold the steering wheel is the 10 am and 2
pm positions, other commonly used positions such as holding the steering
wheel at the 6 pm position may be employed as well. The additional
embodiment can detect when a driver switches between various positions
and warns the driver when none of the standard positions are employed.
The notification model can also incorporate data received from onboard
navigational systems, such as the global positioning satellite (GPS)
system to adjust the notifications depending on the type of road or part
of road the driver is on. Navigational information, such as upcoming
required turns, advanced warnings of dangerous situations (such as
accident prone intersections), and traffic alerts can also be provided
through the vibro-tactile feedback, thereby augmenting real time
navigational and traffic information displays. Additional information
that could be supplied to the model includes time of day (lighting
conditions), how long the driver has been on the road (fatigue factor),
the driver's experience and accident record, etc. Logs of vibro-tactile
sensor data correlated GPS and map data can allow drivers to study and
improve their driving technique. The logs can also be utilized to analyze
accidents and determine if driver inattention was the cause. With
additional sensors, a wrist mounted computer could also measure the pulse
rate of the driver and sense when the driver is more tense than usual and
adjust system parameters accordingly, such as decreasing the volume on
the radio. Integration with other on board vehicle sensors could provide
vibro-tactile feedback if the driver is attempting to change lanes
unsafely.
[0041]While accelerometers mounted to the vehicles chassis help
disambiguate wrist-movement during vehicle motion, further disambiguation
of the wrist mounted vibro-tactile feedback mechanism (IBM's WatchPad)
can be accomplished by integrating separate sensors directly into the
steeling wheel. Radio frequency identification (RFID) readers/sensors
embedded into the steering wheel and an RFID tag integrated into the
wrist mounted device (WatchPad) can differentiate specific wrist
positions that do not indicate driving. For example, if the driver is
resting their hand upon the dashboard, their wrist might be in the
correct position to indicate a driving activity to the sensor system;
however with the RFID sensor also present a determination that the
driver's hand is not upon the steering wheel can be made. The use of RFID
in this embodiment of the invention eliminates the need for
accelerometers in the wrist mounted vibro-tactile feedback mechanism
(WatchPad) for purposes of hand position detection, but the vibro-tactile
feedback feature is still utilized. However, the accelerometers in the
WatchPad can be used to detect other activities, such as drinking,
eating, or holding a cellular phone while the vehicle is in motion.
[0042]By affixing several fixed body worn sensors to the driver, readers
mounted in different positions within the vehicle can detect the overall
driver position as well as the position of the driver's limbs. For
example, it can be determined if the driver's RFID tags or Bluetooth
devices in the driver's shoes are in close proximity to the brake pedal
equipped with an embedded signal reader. Head mounted sensors (such as in
a hat or vision wear) utilizing RFID tags or Bluetooth devices, for
example, can be used (perhaps in conjunction with a camera) to detect the
drivers head position, and if they are dozing off.
[0043]Embedded pressure sensitive switches in the steering wheel can also
be employed to detect when a driver has their hands on the wheel. If a
non-optimal grip condition is determined--such as only one hand on the
wheel for a predetermined (programmable) interval--the onboard vehicle
system can provide a visual and/or audible waning to the driver. In
instances of potential driver incapacitation deduced from both of their
hands being off the steering wheel for a prolonged interval, the onboard
vehicle system can take proactive steps such as turning on the vehicles
flashers, slowing the vehicle down, and initiating an emergency call if
the vehicle is equipped with a two way communication system.
[0044]FIG. 3 is a block diagram of an exemplary system 300 for
implementing the driver monitoring and feedback provided by embodiments
of the present invention. Driver worn sensors 302 are in two-way
electrical communication with a vehicle onboard computer 304 that has a
storage medium 306. A series of vehicle sensors 308 are in electrical
communication with the onboard computer 304. The driver worn sensors 302
can be in the form of a wrist mounted vibro-tactile feedback mechanism
(WatchPad), RFID tags, Bluetooth enabled sensors, and accelerometer
devices, amongst others. The vehicle sensors 308 provide key parameters
such as velocity; engine operating conditions, and vehicle handling
information, etc. The onboard computer 304 gathers inputs from the
sensors 302 and 308, as well as providing feedback to the driver through
sensors 302 and vehicle operating and control equipment 310. In addition,
optional equipment such as GPS 312, in vehicle display 314, and
communication equipment 316 are connected to the onboard computer 304. A
storage unit records the data obtained by the sensors (302,308), and logs
key parameters related to driver behavior and activities, as well as
vehicle performance.
[0045]The flow diagrams depicted herein are just examples. There may be
many variations to these diagrams or the steps (or operations) described
therein without departing from the spirit of the invention. For instance,
the steps may be performed in a differing order, or steps may be added,
deleted or modified. All of these variations are considered a part of the
claimed invention.
[0046]While the preferred embodiments to the invention has been described,
it will be understood that those skilled in the art, both now and in the
future, may make various improvements and enhancements which fall within
the scope of the claims which follow. These claims should be construed to
maintain the proper protection for the invention first described.
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