Characteristics of a Mower Robot with Swing Mower Mechanism by
Simulation
Ryota Suzuki
1
and Yoshihisa Uchida
2
1
Graduate School of Engineering, Aichi Institute of Technology, Yachigusa 1247, Yakausacho, Toyota 470-0392, Japan
2
Aichi Institute of Technology, Yachigusa 1247, Yakausacho, Toyota 470-0392, Japan
Keywords: Mower Robot, Swing Mower Mechanism, Lever-crank Mechanism, Swath, Torque, Velocity, Centroid
Movement, Sideslip, Energy Consumption, Operation Time.
Abstract: This study proposes a new mower robot with a swing mower mechanism for advantages such as a string
trimmer and a wide swath. The proposed swing mower mechanism is designed for installation in the main
body of a four-wheel drive mower robot AMR-D01. The AMR-D01 had overall dimensions as follows: 0.60
m length, 0.50 m width, and 0.30 m height; it weighs 28 kg and maximum velocity is 1.29 m/s. The swing
mower mechanism is based on the lever-crank mechanism and translates motor rotation into swing of the
rotary blade. We model the mechanism and simulate the characteristics of the centroid movement, sideslip,
energy consumption, and operation time to evaluate the swing mower mechanism. The robot velocity is
controlled to prevent the occurrence of the unmown spot. Swath is increased from 0.24 m to 0.62 m by 2.58
using the mechanism. The operation time is also decreased by 1/2.58. The swing mower mechanism does not
have much influence on the robot movement. The change of the static friction coefficient and the slope angle
also does not have much influence on the sideslip of the robot under the present conditions. The energy
consumption increases with the increasing robot velocity.
1 INTRODUCTION
A string trimmer is light and small and can easily
treat; therefore, the trimer is widely used. However, it
requires heavy work, takes time to work, and have a
serious safety issue (Hanidza, 2013). Thus, the string
trimer automation is needed to overcome these
problems. Various string trimmer robots, such as
handle-, passenger-, and remote-type robots, are used
until now.
HAMMER KNIFE (OREC, 2018) and HR663
(YAMABIKO, 2018) are commercialized as the
handle type. These trimmers are very convenient, but
the user must control behind the machine. Ride on
Brush Cutter “RABBIT”(OREC, 2018), RMJ800
(YAMABIKO, 2018), ZHM1520 (ZENOAH, 2018),
and Mid-mower (Jun, 2008) are commercialized and
proposed as passenger type. These are very useful for
large area, but user must ride and drive the machine
and machine is heavy weight. Miimo (Honda, 2018)
and HUSQVARNA AUTOMOWER® 315
(Husqvarna, 2018) are commercialized and proposed
as the remote type. These trimmers are small and safe,
but are mainly for the lawn.
Challenges for practical application of mower
robot are obstacle detection and avoidance,
miniaturization for efficiency and optimization, path
planning and tacking, ability to move on rough terrain,
and efficiency of grass cutting. Several researchers
have proposed to overcome these problems.
Most mower robots are intended to operate on
agricultural land, garden, rice field and river bed.
However, such areas are not free from interactions
with humans, whose safety and legal positions must
be considered. Christiansen et.al. (Christiansen,
2017) proposed a sensor platform in autonomous
mowing operation to detect a human using several
cameras. This platform is for a tractor, thus, the entire
platform is large. In contract, small robots for
agriculture are paying attention for efficiency and
optimization (Basu, 2018). Path planning methods for
agriculture robot are proposed (Urrea, 2015, Wang,
2014, Ohkawa, 2014, Hameed, 2014). These methods
are useful for mower robot. Improvement of
movement performance and efficiency of grass
cutting on small robot are remaining issues.
We develop remote-controlled mower robots in
our laboratory. The developed mower robot is usable
even on a slope ground. However, they have