Human stick balancing is investigated in terms of reaction time delay and sensory dead zones for position and velocity perception using a special combination of delayed state feedback and mismatched predictor feedback as a control model. The corresponding mathematical model is a delay-differential equation with event-driven switching in the control action. Due to the sensory dead zones, initial conditions of the actual state cannot always be provided for an internal-model-based prediction, which indicates that (1) perfect prediction is not possible and (2) the delay in the switching condition cannot be compensated. The imperfection of the predictor is described by the delay mismatch, which is treated as a lumped parameter that creates a transition between perfect predictor feedback (zero delay mismatch) and delayed state feedback (mismatch equal to switching delay). The maximum admissible switching delay (critical delay) is determined numerically based on a practical stabilizability concept. This critical delay is compared to a realistic reference value of 230 ms in order to assess the possible regions of the threshold values for position and velocity perception. The ratio of the angular position and angular velocity for 44 successful balancing trials by 8 human subjects was used to validate the numerical results. Comparison of actual human stick balancing data and numerical simulations based on the mismatched predictor feedback model provided a plausible range of parameters: position detection threshold 1°, velocity detection threshold between 4.24 and 9.35°/s, and delay mismatch around 100–150 ms.

1.
M.
Stankovic
and
O.
Radenkovic
, “
The status of balance in preschool children involved in dance program
,”
Res. Kinesiol.
40
,
113
116
(
2012
).
2.
P.
Gawthrop
,
K.-L.
Lee
,
N.
O’Dwyer
, and
M.
Halaki
, “
Human stick balancing: An intermittent control explanation
,”
Biol. Cybern.
107
,
637
652
(
2013
).
3.
N.
Yoshikawa
,
Y.
Suzuki
,
K.
Kiyono
, and
T.
Nomura
, “
Intermittent feedback-control strategy for stabilizing inverted pendulum on manually controlled cart as analogy to human stick balancing
,”
Front. Comput. Neurosci.
10
,
1
(
2016
).
4.
I. D.
Loram
,
C.
van de Kamp
,
H.
Gollee
, and
P. J.
Gawthrop
, “
Identification of intermittent control in man and machine
,”
J. R. Soc. Interface
9
,
2070
2084
(
2012
).
5.
C. W.
Eurich
and
J. G.
Milton
, “
Noise-induced transitions in human postural sway
,”
Phys. Rev. E
54
,
6681
6684
(
1996
).
6.
J. L.
Cabrera
and
J. G.
Milton
, “
On-off intermittency in a human balancing task
,”
Phys. Rev. Lett.
89
,
158702
(
2002
).
7.
J. L.
Cabrera
and
J. G.
Milton
, “
Stick balancing: On-off intermittency and survival times
,”
Nonlinear Stud.
11
,
305
317
(
2004
).
8.
Y.
Sakaguchi
,
M.
Tanaka
, and
Y.
Inoue
, “
Adaptive intermittent control: A computational model explaining motor intermittency observed in human behavior
,”
Neural Netw.
67
,
92
109
(
2015
).
9.
D. J.
Nagy
,
L.
Bencsik
, and
T.
Insperger
, “
Experimental estimation of tactile reaction delay during stick balancing using cepstral analysis
,”
Mech. Syst. Signal Process.
138
,
106554
(
2020
).
10.
Y.
Suzuki
,
A.
Nakamura
,
M.
Milosevic
,
K.
Nomura
,
T.
Tanahashi
,
T.
Endo
,
S.
Sakoda
,
P.
Morasso
, and
T.
Nomura
, “
Postural instability via a loss of intermittent control in elderly and patients with Parkinson’s disease: A model-based and data-driven approach
,”
Chaos
30
,
113140
(
2020
).
11.
G.
Stepan
,
J. G.
Milton
, and
T.
Insperger
, “
Quantization improves stabilization of dynamical systems with delayed feedback
,”
Chaos
27
,
114306
(
2017
).
12.
T.
Nomura
,
S.
Oshikawa
,
Y.
Suzuki
,
K.
Kiyono
, and
P.
Morasso
, “
Modeling human postural sway using an intermittent control and hemodynamic perturbations
,”
Math. Biosci.
245
,
86
95
(
2013
).
13.
G.
Gyebrószki
,
G.
Csernák
,
J. G.
Milton
, and
T.
Insperger
, “
The effects of sensory quantization and control torque saturation on human balance control
,”
Chaos
31
,
033145
(
2021
).
14.
Y.
Asai
,
Y.
Tasaka
,
K.
Nomura
,
T.
Nomura
,
M.
Casadio
, and
P.
Morasso
, “
A model of postural control in quiet standing: Robust compensation of delay-induced instability using intermittent activation of feedback control
,”
PLoS One
4
,
e6169
(
2009
).
15.
P.
Kowalczyk
, “
A novel route to a Hopf bifurcation scenario in switched systems with dead-zone
,”
Physica D
348
,
60
66
(
2017
).
16.
J.
Milton
,
R.
Meyer
,
M.
Zhvanetsky
,
S.
Ridge
, and
T.
Insperger
, “
Control at stability’s edge minimizes energetic costs: Expert stick balancing
,”
J. R. Soc. Interface
13
,
20160212
(
2016
).
17.
M.
Nordin
and
V. H.
Frankel
,
Basic Biomechanics of the Musculoskeletal System
(
Lea & Febiger
,
1989
).
18.
T.
Insperger
and
J. G.
Milton
,
Delay and Uncertainty in Human Balancing Tasks
(
Springer
,
Cham
,
2021
), ISBN: 978-3-030-84581-0.
19.
E. P.
Hanavan
,
A Mathematical Model of the Human Body
(
Aerospace Medical Research Laboratory
,
Wright-Patterson Air Force Base, OH
,
1964
).
20.
P.
de Leva
, “
Adjustments to Zatsiorsky-Seluyanov’s segment inertia parameters
,”
J. Biomech.
29
,
1223
1230
(
1996
).
21.
J.
Milton
,
J. L.
Cabrera
,
T.
Ohira
,
S.
Tajima
,
Y.
Tonosaki
,
C. W.
Eurich
, and
S. A.
Campbell
, “
The time-delayed inverted pendulum: Implications for human balance control
,”
Chaos
19
,
026110
(
2009
).
22.
M.
Kawato
, “
Internal models for motor control and trajectory planning
,”
Curr. Opin. Neurobiol.
9
,
718
727
(
1999
).
23.
M.
Desmurget
and
S.
Grafton
, “
Forward modeling allows feedback control for fast reaching movements
,”
Trends Cognit. Sci.
4
,
423
431
(
2000
).
24.
B.
Mehta
and
S.
Schaal
, “
Forward models in visuomotor control
,”
J. Neurophysiol.
88
,
942
953
(
2002
).
25.
J. G.
Betts
,
P.
DeSaix
, and
E.
Johnson
,
Anatomy and Physiology
(
OpenStax College, XanEdu Publishing Inc.
,
2013
).
26.
H. T.
Lawless
and
H.
Heymann
,
Sensory Evaluation of Food: Principles and Practices
(
Springer-Verlag
,
1999
).
27.
J. G.
Milton
,
J. L.
Cabrera
, and
T.
Ohira
, “
Unstable dynamical systems: Delays, noise and control
,”
Europhys. Lett.
83
,
48001
(
2008
).
28.
L. A.
Lipsitz
,
M.
Lough
,
J.
Niemi
,
T.
Travison
,
H.
Howlett
, and
B.
Manor
, “
A shoe insole delivering subsensory vibratory noise improves balance and gait in healthy elderly people
,”
Arch. Phys. Med. Rehabil.
96
,
432
439
(
2015
).
29.
L.
Gammaitoni
, “
Stochastic resonance and the dithering effect in threshold physical systems
,”
Phys. Rev. E
52
,
4691
4698
(
1995
).
30.
J.
Hunter
,
J.
Milton
,
H.
Lüdtke
,
B.
Wilhelm
, and
H.
Wilhelm
, “
Spontaneous fluctuations in pupil size are not triggered by lens accommodation
,”
Vision Res.
40
,
567
573
(
2000
).
31.
P.
Kowalczyk
,
S.
Nema
,
P.
Glendinning
,
I.
Loram
, and
M.
Brown
, “
Auto-regressive moving average analysis of linear and discontinuous models of human balance during quiet standing
,”
Chaos
24
,
022101
(
2014
).
32.
R.
Nijhawan
and
S.
Wu
, “
Compensating time delays with neural predictions: Are predictions sensory or motor?
,”
Philos. Trans. A: Math. Phys. Eng. Sci.
367
,
1063
1078
(
2009
).
33.
P.
Kowalczyk
,
P.
Glendinning
,
M.
Brown
,
G.
Medrano-Cerda
,
H.
Dallali
, and
J.
Shapiro
, “
Modelling human balance using switched systems with linear feedback control
,”
J. R. Soc. Interface
9
,
234
245
(
2012
).
34.
G.
Stepan
, “
Delay effects in the human sensory system during balancing
,”
Philos. Trans. R. Soc. A
367
,
1195
1212
(
2009
).
35.
G.
Stepan
,
Retarded Dynamical Systems
(
Longman
,
1989
).
36.
B. A.
Kovacs
,
J.
Milton
, and
T.
Insperger
, “
Virtual stick balancing: Sensorimotor uncertainties related to angular displacement and velocity
,”
J. R. Soc. Open Sci.
6
,
191006
(
2019
).
37.
R. R.
Zana
and
A.
Zelei
, “
Introduction of a complex reaction time tester instrument
,”
Period. Polytech. Mech. Eng.
64
,
20
30
(
2019
).
38.
T.
Insperger
and
J.
Milton
, “
Sensory uncertainty and stick balancing at the fingertip
,”
Biol. Cybern.
108
,
85
101
(
2014
).
39.
T.
Insperger
and
G.
Stepan
,
Semi-Discretization for Time-Delay Systems, Stability and Engineering Applications
(
Springer-Verlag
,
New York
,
2011
).
40.
J.
Milton
and
T.
Insperger
, “
Acting together, destabilizing influences can stabilize human balance
,”
Philos. Trans. R. Soc. A
377
,
20180126
(
2019
).
41.
M. M.
Gomez
,
M.
Sadeghpour
,
M. R.
Bennett
,
G.
Orosz
, and
R. M.
Murray
, “
Stability of systems with stochastic delays and applications to genetic regulatory networks
,”
Soc. Ind. Appl. Math. J. Appl. Dyn. Syst.
15
,
1844
1873
(
2016
).
42.
H. T.
Sykora
,
D.
Bachrathy
, and
G.
Stepan
, “
Stochastic semi-discretization for linear stochastic delay differential equations
,”
Int. J. Numer. Methods Eng.
119
,
879
898
(
2019
).
43.
H. T.
Sykora
,
M.
Sadeghpour
,
J. I.
Ge
,
D.
Bachrathy
, and
G.
Orosz
, “
On the moment dynamics of stochastically delayed linear control systems
,”
Int. J. Robust Nonlinear Control
30
,
8074
8097
(
2020
).
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