Intermittent
Electrical Contact Resistance
as a Contributory Factor in the Loss
of Automobile Speed Control Functional
Integrity IEEE
ACCESS March 19 2014
Abstract:
For three decades, sudden acceleration (SA)
incidents have been reported, where automobilesaccelerate
without warning. These incidents are often
diagnosed as No Fault Found (NFF). Investigators
who follow the line of diagnostic reasoning from
the 1989 NHTSA SA reporttend to
conclude that SAs are caused bydriver
pedal error.This paper reviews the diagnostic processin the
NHTSA report and finds (1) that it assumes that an
intermittent electronic malfunction should be
reproducibleeither
through in-vehicle or laboratory bench tests
without saying why and(2)that
the consequence of this assumption, for which
there appears to be no forensic precedent, isto
re-categorizepossible intermittent electronic failures
asproven
to be non-electronic. Showing that the supposedly
inescapable conclusions of the NHTSA report
concerning electronic malfunctions are without
foundation opens the way for the paper to discusselectronic
intermittency as a potential factor in SA
incidents. It then reports a simple practical
experiment that showshow
mechanically-induced electrical contact
intermittencies cangenerate false speed signalsthat an
automobile speed control system may accept as true
and that do nottrigger any diagnostic fault codes. Since
the generation of accurate speed signals is
essential for the proper functioning of a number
of other automobile safety-critical control
systems, the apparent ease with which false speed
signals can be generated by vibration of a poor
electrical contact is obviously a matter of
general concern. Variousways ofreducing
the likelihood of SAs are discussed, including
electrical contact improvements to reduce the
likelihood of generating false speed signals,
improved battery maintenance, and the
incorporation of an independent fail-safe that
reduces engine power in an emergency,such as
a kill switch. This
article has been accepted for publication in
a future issue of this journal, but has not
been fully edited. Content may change prior
to final publication. Citation information:
DOI 10.1109/ACCESS.2014.2313296, IEEE Access
Anderson,
A. F.
Reliability in
Electromagnetic Systems: The role of
electrical contact resistance in maintaining
automobile speed control system integrity.IET Colloquium
on Reliability in Electromagnetic Systems,
14-25 May 2007, Paris, France. Abstract: Electromagnetic
systems
depend
upon
the integrity of electrical connections. An
intermittent speed sensor connection is shown to
generate a false speed signal that may allow an
automobile speed control system to engage at low
speed and cause a sudden acceleration.
Preventive measures are discussed. The current
approach to controlling uncommanded sudden
accelerations seems to rely upon the driver
braking against full engine power to bring the
vehicle to a halt. More effective and safer
control would be achieved by cutting off the
fuel supply the moment that an uncommanded wide
open throttle condition was detected, thereby
preventing the sudden acceleration. PDF Copies
obtainable by clicking here or
from the author by e-mail : antony.anderson@onyxnet.co.uk
Anderson, A. F.
Digital Speedometer
Fluctuating Readings Diagnostic
Engineering Sept/Oct 2006 pages
901-903
Abstract: An explanation of how intermittency in
speed sensor connections in the presence of
vibration may generate a false speed signal that
the electronic speedometer will accept as
valid. Electrical contacts have the
potential for causing all manner of electronic
mayhem beyond the example given here and should
never be taken for granted.
Tavner, P.J.,
Anderson A. F.
Core faults in
large generators
IEE Proceedings - Electrical Power Applications -
November 2005 - Vol 152. Issue 6. p 1427-1439 Abstract:A core fault is a failure in the
laminated core ofa large electrical
machine. Such faults are relatively rare butwhen they occur, the value of the machine
and itsimportance mean that the
investigation of the failure assumes ahigh
priority. On many occasions the details of such
failuresassume major commercial
significance, therefore failure investigations
have, of necessity,to be handled in
a confidential manner, touching as theydo
on the design, manufacture, operation and
insurance of largeelectrical plant.
There has therefore been no published literature
oncore faults. However, the
scientific principles of the mechanisms atwork have been studied in considerable
detail and papers publishedon those
principles in the international literature. This
paper bringstogether that
literature and those scientific principles,
giving details ofthe underlying
design, constructional and operational factors
which affect thesefaults. New
evidence is presented of the underlying factors
whichallow core faults to initiate
and grow. The paper willallow
engineers to analyse such faults, draw rational
conclusions onthe causes for each
occasion and devise suitable repair/rebuild
strategiesapplicable to that
situation. Copies
obtainable from the IEE
by subscription. Alternatively e-mail Antony
Anderson and
ask for a pdf file
Anderson,
A. F.
A chance encounter with
William Sturgeon Electronics and Power
February 1986 pp 129 - 131
What would the 18th century pioneers think
of today's technology? An exclusive interview
with William Sturgeon (1783-1850) the inventor
of the electromagnet. Download
PDF File http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5188224
Anderson,
A. F.
William Henley : Imagination
without discipline Electronics and Power August
1985 pp 593 - 597
William Henley (1813-1882), electrical
instrument maker and cable manufacturer,
inventor and entrepreneur was a man of immense
energy and self confidence and played an
important role in the early development of the
electrical engineering industry. We can learn a
great deal from him: especially how not to run
an engineering company. http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?tp=&arnumber=5188637
Anderson,
A. F.
William Henley, pioneer
electrical instrument maker and cable
manufacturer, 1813 to 1882
IEE Proceedings, Vol 132, Pt. A,
No 4, July 1985 pp 249 - 261 Abstract: William
Henley
provides a case history of a pioneer
manufacturer of electrical instruments and
equipment, who expanded from instrument making
into the production and laying of submarine
cables. At one time he employed 2000 men and
owned three cable laying ships. By 1874 he had
expanded his firm beyond what one could manage
and, when the recession came, he failed. He had
lived frugally, but instead of using some of the
profits to build up reserves, he spent heavily
on expansion and borrowed heavily. Henley is an
object lesson to all inventor-entrepreneurs:
watch your cash flow and be prepared to
delegate. His personal management style did not
adapt to the growth of the business and to the
need for sound administration. The firm had to
be reconstituted without him, and then W.T.
Henley's Telegraph Works Ltd. recovered and
enjoyed subsequent success. [0ffprints of paper
still available on request from AFA] http://ieeexplore.ieee.org/Xplore/login.jsp?url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel5%2F5176125%2F5187733%2F05188637.pdf%3Farnumber%3D5188637&authDecision=-203
Le
Ny,
R.
Guile, A .E.,
Anderson, A. F.
Mechanism
of "Meandering" Breakdown of Insulation
in an Electrical Machine. Proceedings of
First International Conference on
Conduction and Breakdown in Solid Dielectrics.
Université Paul Sabatier
TOULOUSE -France July 4-8, 1983 Paper H9 p.
395-398. Abstract: In a previous paper, Anderson and Guile
described an unusual type of interlaminar
insulation breakdown found in the stator core of
an electrical machine, which can lead to
increased losses. The damage revealed by
scanning electron microscopy was compared with
that caused by arc discharges, but there were
features of worm-like metallic filaments which
could not be explained. In the present paper,
comparison is made with atmospheric corrosion
phenomenon of electrochemical origin, which can
occur if the relative humidity lies within a
critical range. In this "filoform" corrosion in
metals covered by protective films, wormlike
filamentary corrosion can begin from such points
as inclusions or scattered hygroscopic salts,
with the head of the filament supplied with
water from the surrounding air by osmotic action
due to the high concentration of dissolved
ferrous ions. The heterogenious oxygen diffusion
in the head produces a differential oxygen
concentration cell which leads to the
development of filogorm corrosion. The active
head with its blue-green colour characteristic
of ferrous ions is reflected if it strikes an
inactive tail of another filament (which appears
as red-brown due to ferric oxide). Since growing
filaments cannot cross inactive tails, they can
become trapped and die as available space
diminishes. SEM photographs of metallic
filaments on insulated laminations from a
machine will be shown, and it will be seen that,
despite the differences in gas and humidity
involved in the two cases, there are significant
similarities. Discussion will be given of the
similarities and differences between the
filoform corrosion and the interlaminar
breakdown, so as to attempt to improve
understanding of the processes involved.
Platt,
R.,
Kerr, L.C.,
Anderson, A. F.
Measuring Flux and
Interlaminar Voltage in Turbine
Generator End Regions. Int. Conf.
Electrical Machines - Design
and Applications IEE London
13-15 July 1982 p. 201-205. Abstract:
This paper describes the general approach to the
measurement of flux and interlaminar voltages in
turbogenerator end regions.Construction and
locations of typical search coils are shown.
Some selected results of measurements of
interlaminar voltages in the end region are
given which show typical values of 5v
peak-to-peak at 50 Hz. The induced voltage in a
back-of-core search coil at the core end is
shown to rise sharply under short circuit
conditions, whereas in a similar coil well away
from the core end the voltage collapses. As far
as is known, this paper records the first
occasion on which attempts were made to measure
transient back-of-core flux leakage phenomena
on a large electrical under sudden short
circuit conditions. Download
PDF File
Anderson,
A.
F.,
Bedford, T.,
Craddock, A. F.
Transient leakage flux in
small universal motors.
IEE PROC., Vol 128, Pt. B, No 5,
September 1981 p. 254-254 Abstract: This
communication
reports an investigation into the transient
back-of-core flux that arises in a small
universal motor. A substantial leakage flux has
been shown to exist under starting conditions
which is caused by excess field ampere turns
saturating the core and forcing the flux into
the back of core region. Download PDF File 550 kB
Magnetic fields and
inductances of helical windings with 120
degree phasebands Electrical Machines and
Electromechanics 6: 323-335 Hemisphere
Publishing Corporation. 1981. Abstract: In
the development of superconducting a.c.
generators the essential air-cored nature of the
generator, and the larte power output per unit
length, suggests that conventional armature
windings may not necessarily be the most
suitable. One possible alternative is the
helical armature winding and has been proposed
both as a means of obtaining a uniformly
supported armature structure and for generating
at transmission line voltages. This paper
discusses the peculiarities of helical windings,
and in particular those with 60 degree and 120
degree phase-bands. Magnetic field and
indusctance measurements are made on a three
phase model with a phase spread of 120 degrees
and compared with calculated values using a
previously published theory. Computed and
measured values of synchronous inductance agree
to within 1%.
Anderson,
A. F.
Contribution to discussion on
Variable-speed switched-reluctance motor
systems before IEE Power Divison
Professional Groups p1 and P6 8th December 1980
IEE Proc., Vol 128, Pt B, No 5 September 1981 p
265.
Anderson, A, F.,
Bumby, J. R.,
Hassall, B. I.
Analysis of helical armature
windings with particular reference to
superconducting a.c. generators IEE Proc.,
Vol 127, Pt c, No 3, May 1980 pp 129 - 144 Abstract:
An unusual form of helical polyphase armature
winding is described in which conductors lie on
a helix of constant radius as they pass from one
end of the machine to the other. There are no
end windings. An analysis of the winding is
performed which allows analytical expression for
the flux densities and machine reactances to be
found. Measured and calculated values of
synchronous reactance agree to within 2%. Some
of the more unusual properties of helical
windings are discussed. See Helical WindingDownload PDF
File of Paper
Anderson
A.
F.,
Steel,
J.G, Reece, A. J. B., Carpenter C.J., Preston.
T. W., Phemister, T.G., Smith, R.,
Hammond, P., Jackson, R. J., Tavner, P.J.,
Penman, J., Stoll, R.L., Lorch,
H.O., Howe, D.
Contributions
to
'Discussion
on
Interlamination
voltages in large Turbine Generators and
Influence of winding design on the axial
flux in laminated-stator cores and
Examination of flux distribution in segmented
stator cores' IEE PROC, Vol
127, Pt. C. No2 March 1980 p 114-115.
Anderson,
A.
F.,
Guile, A. E.
An
unusual
type of interlaminar breakdown found in an
electrical machine. Sixth International
Conference on 'Gas Discharges and their
Applications' Heriot-Watt University: 8-11
September 1980. Abstract:
The stator cores of large electrical machinews
are made up of segmented laminations separated
by layers of varnish to minimise eddy currents
and core losses. From time to time the
insulation is subjected to appreciable voltage
stress, e.g. during start up of an induction
motor or during system disturbances for a
generator. These stresses are highest nearest
the ends of the core where leakage fluxes are
highest. A localised breakdown of insulation
between two adjacent layers of laminations may
then occur and, if this becomes permanent, it
will cause increased eddy currents and
higher losses at the breakdown site. Hence
insulation quality is important in machines and
thus understanding of the mechanism of
interlaminar breakdown is necessary. However,
because of the number of laminations in a
machine, direct monitoring of interlaminar
voltages is difficult. Some progress has been
made recently by laser welding interlaminar
probes on a 500 MW machine and a 120 MW machine,
but the main sources of information still
remains the detailed examination of individual
laminations on machines. It was during such an
examination that examples of interlaminar
breakdown were found which differed from any
previously known to the authors, and this paper
reports the unusual features with a view to
stimulating discussion. A description of a
'meandering' interlaminar breakdown follows. Download PDF
file of this paper
Sparks from Steam : The story
of the Armstrong hydroelectric generator.Electronics and Power January 1978 pp 50
- 53. Abstract:
The mysterious explosion of three large oil
tankers in 1969 would not appear to have
connection with the peculiar happenings in an
isolated Northumberland Colliery in 1940.
However, there might have been no explosions had
the dangers of the electrification of wet steam
and high pressure water been better appreciated
by those responsible for the cleaning out of
large oil tanks. A description of the
investigation carried out at Seghill Colliery in
the autumn of 1840 by William Armstrong, later
Lord Armstrong into static electrical discharge
resulting from a steam leak in a stationery
boiler. A description of Armstrong's
"hydro-electric" generator follows , of
which multi-jet versions were built, one
for the London Polytechnic Institution and
one for export to the USA. Other effects
of the electrification of steam are described.Download PDF file
Anderson,
A. F.
Unusual Electric Machines.Electronics and Power 14 November 1974 pp
979 - 983 [ based on a lecture given to the IEE
North Eastern Graduate and Student Section 29th
April 1974]
Anderson,
A. F.
Some early experiments in
applied electromagnetism : Robert Davidson -
Electromagnetician Extraordinary -
Pioneer of Electric Traction. Lecture to
the Royal Scottish Society of Arts 10 March 1975
[ Also presented at IEE History of Electrical
Engineering Conference 1975]
Appleton,
A.D.,
Anderson, A. F., Ross, J. S. H.
A
discussion on large superconducting A.C. Generators
Paper A 3 pages 1 - 12. Date & Place unknown
Appleton, A. D.,
Anderson A. F.
A review of the critical
aspects of superconducting generators.
Paper M-2 Applied Superconductivity Conference
Annapolis 1972. Abstract:
This paper reviews the development of
superconducting generators undertaken by IRD on
behalf of C.A. Parsons and Company Ltd.An outline design of a
machine concept is presented with a discussion
of the more critical development problems.An account is given of
the manner in which performance is influenced by
machine geometry, in particular by
inter-winding coupling factors on substransient
reactance. The principal mechanisms causing
machine losses are reviewed and the techniques
used for their prediction and minimisation are
outlined. PDF File
available 2.2 Mb.
Cruickshank, A. J. O.,
Anderson, A. F.,
Menzies, R. W.
Stability of reluctance
motors from freely accelerating torque speed
curves Transactions Paper T 72 049-0 IEEE
Winter Meeting NY Jan 30-Feb 4 1972. Abstract:
The limits of stability in reluctance machines
are known to be narrow, especially in machines
of improved design with high reactance ratio.
These stability limits can usefully be
investigated with the aid of computed and
measured freely accelerating torque speed
curves. The machine equations are developed
using a frame of reference fixed with respect to
the rotor. Machine performance is then
simulated on an analogue computer. A large
number of freely accelerating torque speed
curves are then generated for different values
of machine parameters. The model is designed to
cope simply with different motors and is based
on a per unit system. All parameters can be
simply varied, so that their effect on
performance can be demonstrated. The torque
speed curves that result can be said to be
characteristic of a machine with given
parameters and contain information about
starting torque, transient torque dips,
synchronisation ability and stability.
Since changes in parameters cause marked changes
in shape of the freely accelerating torque speed
curve, it is possible, bu matching the results
obtained from a practical test with those from a
computer study, to determine where the total
performance of the machine lies with respect to
the optimum and to decide what changes are
necessary to improve design. Download PDF File IEEE Abstract
Cruickshank, A. J. O.,
Anderson, A. F.,
Menzies, R. W.
Theory and performance of
reluctance motors with axially laminated
anisotropic rotors. Proc IEE, Vol 118, No
7, July 1971 pp 887 - 894 Abstract:
A theoretical and practical study is given
of reluctance motors having rotors
constructed from axially anisotropic cores, as
proposed in an earlier paper. The experimental
work has led to the development of a practical
motor of high performance, capable of a large
maximum output without detriment to overall
performance or stability. In addition, the broad
field of reluctance motors and their features
are reviewed, and an attempt is made to
integrate developments. A full bibliography is
provided. [53 references from 1923 to 1970] Download PDF
File
Cruickshank,
A. J. O.,
Anderson, A. F.
Stability of Reluctance
Machines. [Contribution to discussion of
paper by Lawrenson, Bowes and Mathur Proc IEE,
1971 118 (6), pp. 777-783] Proc IEE, Vol 118, No
9, September 1971 pp 1289-1290
Cruickshank,
A.
J.
O.,
Anderson, A. F.
Axially-laminated reluctance
synchronous motors. Proceedings of EM70
conference, University of Dundee, Dundee,
Scotland, paper 40, pp 40-1 to 40-4.
Cruickshank,
A.
J.
O.,
Anderson, A. F.
Transient Performance of
Reluctance Synchronous Motors. Proceedings
Fifth Universities Power Engineering Conference,
Swansea, January 1970
Cruickshank,
A.
J.
O.,
Anderson, A. F.
Contribution to discussion of
papers 5248 P, 5270P and 5540P on Reluctance
Motors. Proc IEE, Vol 115, No 9, September
1968 page 1285
Anderson,
A. F.
A New Type of Reluctance
Motor. IEE Students' Quarterly Journal
September 1968 pages 19 - 24
Cruickshank,
A.
J.
O.,
Anderson, A. F.,
Menzies R.W.
A New Development in
Reluctance Motors. St Andrews
University Engineers Year Book 1966 pages 21-26
Cruickshank,
A.
J.
O.,
Menzies R.W.,
Anderson, A. F.
Axially Laminated Anisotropic
Rotors for reluctance Motors. Proc. IEE,
Vol 113, No 12, December 1966 pages 2058 - 2060 Abstract:
An interim report is given on work on reluctance
motors presently being carried out in the
Department of Electrical Engineering, University
of St Andrews, Queen's College, Dundee. A
description is given of a new type of rotor, in
which strip-wound axial laminations of
magnetically anisotropic material replace
conventional rotor stampings. 10 references
1923-1966.
Anderson,
A.F.,
Cruickshank, A.J.O.
Development of the reluctance
motor. Electronics and Power, 1966, 12, p
48
Patents
Number
Inventors
Prov. Spec. Filed
Spec. filed
Spec. Publ.
Title
1 576 619
Anderson, A.F., Anderson, R.
13.05.1976
05.05.1977
08.10.1980
Improvements
in
and relating to D.C. supplies [ Onboard power supply for
rotating mahines]
1 508 793
Henderson, Anderson,
Hickling, Ralph, Young
02.04.1974
01.04.1975
26.04.1978
Improvements
in
and relating to dynamo electric machines [Generator stator construction]
1 482 411
Anderson
25.05.1973
30.07.1974
10.08.1977
Rotary machine having a
cooling system for circulation of liquid
coolant to the rotor
1 455 818
Anderson
31.10.1972
30.10.1973
17.11.1976
Improvements in and relating
to Dynamo Electric Machines
US Pat
3,761,752
Anderson
01.05.1972
25.09.1973
Dynamoelectric
machine winding support [Heocal stator
winding for AC Machines]
1 395 152
Ross, Anderson MacNab
01.02.1971
01.05.1972
21.05.1975
Alternating Current
Dynamo-Electric Machine Windings
[Helical stator winding for AC machines]
1 183 630
Cruickshank, Anderson
11.03.1970
Rotor for Reluctance Machine
1 114 562
Cruickshank, Anderson
28.05.1968
Rotor for Dynamo-Electric
Machine [Axially
laminated rotor]
1 114 561
Cruickshank, Anderson
22.05.1968
Dynamo-Electric Machine
[A thyristor driven switched field
reluctance motor]
A
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