Citation: Mikolajczyk, T.;
Mikołajewska, E.; Al-Shuka, H.F.N.;
Malinowski, T.; Kłodowski, A.;
Pimenov, D.Y.; Paczkowski, T.; Hu, F.;
Giasin, K.; Mikołajewski, D.; et al.
Recent Advances in Bipedal Walking
Robots: Review of Gait, Drive,
Sensors and Control Systems. Sensors
2022, 22, 4440. https://doi.org/
10.3390/s22124440
Academic Editors: Abolfazl Zaraki
and Hamed Rahimi Nohooji
Received: 20 April 2022
Accepted: 9 June 2022
Published: 12 June 2022
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Review
Recent Advances in Bipedal Walking Robots: Review of Gait,
Drive, Sensors and Control Systems
Tadeusz Mikolajczyk
1,
* , Emilia Mikołajewska
2,3
, Hayder F. N. Al-Shuka
4,5
, Tomasz Malinowski
1
,
Adam Kłodowski
6
, Danil Yurievich Pimenov
7,
* , Tomasz Paczkowski
1
, Fuwen Hu
8
, Khaled Giasin
9
,
Dariusz Mikołajewski
10
and Marek Macko
11
1
Department of Production Engineering, Bydgoszcz University of Science and Technology,
Al. Prof. S. Kaliskiego 7, 85-796 Bydgoszcz, Poland; techniczny.tomasz@gmail.com (T.M.);
tompacz@pbs.edu.pl (T.P.)
2
Department of Physiotherapy, LudwikRydygier Collegium Medicum in Bydgoszcz,
Nicolaus Copernicus University, 87-100 Torun, Poland; e.mikolajewska@wp.pl
3
Neurocognitive Laboratory, Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University,
87-100 Torun, Poland
4
Department of Aeronautical Engineering, Baghdad University, Baghdad 10001, Iraq;
dr.hayder.f.n@coeng.uobaghdad.edu.iq
5
School of Control Science and Engineering, Shandong University, Jinan 250100, China
6
Laboratory of machine Design, Lappeenranta University of Technology, 53850 Lappeenranta, Finland;
adam.klodowski@lut.fi
7
Department of Automated Mechanical Engineering, South Ural State University, Lenin Prosp. 76,
454080 Chelyabinsk, Russia
8
School of Mechanical and Material Engineering, North China University of Technology, Beijing 100144, China;
hfw@ncut.edu.cn
9
School of Mechanical and Design Engineering, University of Portsmouth, Portsmouth PO1 3DJ, UK;
khaled.giasin@port.ac.uk
10
Institute of Computer Science, Kazimierz Wielki University, 85-064 Bydgoszcz, Poland; dmikolaj@ukw.edu.pl
11
Faculty of Mechatronics, Kazimierz Wielki University, 85-064 Bydgoszcz, Poland; mackomar@ukw.edu.pl
* Correspondence: tami@pbs.edu.pl (T.M.); danil_u@rambler.ru (D.Y.P.)
Abstract:
Currently, there is an intensive development of bipedal walking robots. The most known
solutions are based on the use of the principles of human gait created in nature during evolution.
Modernbipedal robots are also based on the locomotion manners of birds. This review presents
the current state of the art of bipedal walking robots based on natural bipedal movements (human
and bird) as well as on innovative synthetic solutions. Firstly, an overview of the scientific analysis
of human gait is provided as a basis for the design of bipedal robots. The full human gait cycle
that consists of two main phases is analysed and the attention is paid to the problem of balance
and stability, especially in the single support phase when the bipedal movement is unstable. The
influences of passive or active gait on energy demand are also discussed. Most studies are explored
based on the zero moment. Furthermore, a review of the knowledge on the specific locomotor
characteristics of birds, whose kinematics are derived from dinosaurs and provide them with both
walking and running abilities, is presented. Secondly, many types of bipedal robot solutions are
reviewed, which include nature-inspired robots (human-like and birdlike robots) and innovative
robots using new heuristic, synthetic ideas for locomotion. Totally 45 robotic solutions are gathered
by thebibliographic search method. Atlas was mentioned as one of the most perfect human-like
robots, while the birdlike robot cases were Cassie and Digit. Innovative robots are presented, such
asslider robot without knees, robots with rotating feet (3 and 4 degrees of freedom), and the hybrid
robot Leo, which can walk on surfaces and fly. In particular, the paper describes in detail the robots’
propulsion systems (electric, hydraulic), the structure of the lower limb (serial, parallel, mixed
mechanisms), the types and structures of control and sensor systems, and the energy efficiency of the
robots. Terrain roughness recognition systems using different sensor systems based on light detection
and ranging or multiple cameras are introduced. A comparison of performance, control and sensor
systems, drive systems, and achievements of known human-like and birdlike robots is provided.
Thirdly, for the first time, the review comments on the future of bipedal robots in relation to the
Sensors 2022, 22, 4440. https://doi.org/10.3390/s22124440 https://www.mdpi.com/journal/sensors
