NewTechnology

Development of Feeder “ TRINITTE ” forPicking Robots

Shuhei MATSUI*NTN has developed a new parts feeder (TRINITTE) that combines aconventional parts feeder and a rotating disk and is developing it into afield that transcends the field of the conventional parts feeder.
In this article, I will explain the outline, features and specifications ofTRINITTE.

1. Introduction
There has been a rapid expansion in automationand manpower reduction globally using industrial
robots with the aim of increasing productivity at
the manufacturing site. This situation has occurredbecause of the diversification of consumer needs,
and the shift from mass production to “high-mixlow-volume production”. For parts feeders, there is aneed to reduce production changeover time due tothe support for a wide variety of workpieces, and aneed to decrease brief stoppages in production due toworkpiece jamming (improve availability factor).
For the conventional parts feeder and picking robot
combination, the workpieces are selected and sorted
in a bowl feeder were stored in straight feeders, adelivery mechanism used to deliver each workpiece,
and then the workpieces were picked up by a picking
robot. This setup had issues, which were that only
certain workpieces could be handled, many working
components were required, and workpieces became
jammed when sorting or storing them inside feeders.
However, parts supply devices are now being soldfor robots on the premise that sensing technology isused in combination with picking robots. Parts supply
devices for robots use 3-axis vibration technology
to change the posture of workpieces in the picking
area and to separate workpieces if they are too close
to each other, and a camera is used to detect theworkpiece position so that the picking robot can pickup the workpiece. The issue with this setup is that ifa workpiece with a pickable posture is not present inthe picking area, the machine operates to change theposture, so the robot stops during this time.
NTN has developed TRINITTE to solve these issues.

* NTN Technical Service Corp., Precision Equipment Division96

NTN TECHNICAL REVIEW No.89

2. Overview
Fig. 1 shows the system configuration. TRINITTE
comprises a motor-driven rotating disk arrangedon the outer circumference of a conventional bowl
feeder, and an encoder attached to the rotating disk.
A camera and picking robot are connected to thesystem so that the picking robot can import pulse
signals output from TRINITTE and image processing
signals obtained from the camera.
The following explains the full sequence of thepicking system that combines TRINITTE with a robot.
Workpieces deposited in the bowl are sorted ina single-row single-layer arrangement by the bowl
feeder, then supplied onto the rotating disk. The
workpieces supplied onto the rotating disk are picked
up without stopping the rotating disk using a robot
arc conveyor tracking function*1, then supplied tothe next process. Any workpieces that could not bepicked up are also collected inside the bowl feeder via
a workpiece collection opening located on the rotating
disk. These recovered workpieces are once again
supplied via the bowl feeder onto the rotating disk.
*1 Vision sensors are used to detect the position of a workpieceat any position on the rotating disk. This information andinformation from the encoder is used by the robot so that it
can follow the rotating disk and pick up the workpiece fromthe disk.

Camera

Scalar robot

Workpiece sortand supplyPickingBowl

Rotating disk
TRINITTE main body

Workpiece collection opening

Fig. 1 System configuration

In addition to supplying workpieces to the robot
using the rotating disk, this product has a simple andcompact structure that can also separate workpieces
and recover unpicked workpieces, enabling it toperform three tasks in a single unit.
Increasing the rotational speed of the rotating
disk more than the supply speed of the bowl feeder
enables workpieces that are ejected in a joinedmanner to be separated, making it easier for the robot
to pick up. Workpieces that could not be picked upby the robot are also collected inside the bowl so thatthey can be supplied once again onto the rotating disk
(Fig. 3).

3. Features
TRINITTE has the following features.
(1) Saves space
TRINITTE is different to conventional parts feeders
and uses a rotating disk to supply workpieces, so
it does not require a straight feeder, a chute or aworkpiece separating mechanism. Therefore, as
shown in Fig. 2, the number of working components
can be reduced to cut the footprint by approximately
30 %.

Attachment
Rotating disk

Workpiece

Bowl
Conventional parts feeder(a) Workpiece separation
Workpiece
collection opening

Separating mechanism
ChuteWorkpiece

Rotating disk
Bowl

Straight feeder

30 %reduction

TRINITTE

Fig.2 Comparison of size between conventional parts
feeder and TRINITTE(b) Workpiece recovery
Fig. 3 Workpiece separation and recovery(2) Reduces brief stoppages
Conventional parts feeders use an attachment witha complex structure installed on the bowl feeder toarrange the posture of workpieces in the bowl feeder.
This complex structure makes it easy for workpieces
to become jammed when they are caught on theattachment, etc.
TRINITTE links the vision system and picking robot
together so that the attachment installed on the bowl
feeder has only a simple structure to perform tasks
such as aligning the orientation of workpieces. Since
the attachment can be simplified, continuous supplyof stable parts is achieved.
(3) Reduces robot wait time
TRINITTE ensures that workpieces are aligned sothat their orientation matches in a single-row

NTN TECHNICAL REVIEW No.8997

Development of Feeder “TRINITTE” for Picking Robots
single-layer arrangement and enables a continuous
supply of workpieces at the picking area of the picking
robot. Therefore, workpieces on the rotating disk
can always be picked up and the robot can continue
picking up workpieces. Furthermore, as mentioned
previously, the use of an arc conveyor tracking
function on the picking robot enables constantoperation without stopping the rotating disk, so thisincreases the equipment availability factor.
(4) Improves versatility
TRINITTE can simplify the attachment installed on
the bowl feeder, which makes it possible to support awide variety of workpieces (Fig. 4) by making simple
adjustments only, without changing the bowl feeder.
This can reduce the time required for productionchangeover.
Additionally, workpieces that could not be stored
and could not be supported with conventional parts
feeders, or irregular-shaped workpieces can now besupported, demonstrating that this is a device withhigh versatility.

(a) Fuses(b) Resin bushing

4. Specifications
TRINITTE has a lineup of 3 distinct types of bowl
sizes according to the size of the workpiece. Table 1shows the main specifications.
Table 1 Specifications
Part numberDimensions

K-UP301
K-UP302
K-UP303
Length 350 mm Length 500 mm Length 700 mm
Width 350 mm Width 500 mm Width 700 mm
Height 320 mm Height 370 mm Height 510 mm
φ190 mm φ320 mm φ420 mm

Bowl diameter
Power supply
AC200 V 50/60 Hz
voltage
Mass
38 kg
85 kg
200 kgOuter
φ344 mm φ494 mm φ694 mm
diameterRotating Rotational
1.3 to 6.5 min-1
countdisk
Rotational
0.05 to 0.20 m/s
0.05 to 0.30 m/s
speed
Part number ofcontroller for bowl
K-ECL25
K-ECH45
feeder (manufacturedby NTN)
Part number ofcontroller for motor
DSCD15JC(Manufactured byOriental Motor)
Encoder part number
E6B2-CWZ1X 1000P/RO.5M(Manufactured byOmron)

5. Summary(c) Connectors(d) Resin blocks

Fig. 4 A wide variety of workpieces are supported
using the same bowl

Photo of author

Shuhei MATSUINTN Technical
Service Corp.,
Precision Equipment
Division98

NTN TECHNICAL REVIEW No.89

This paper explained the outline, features, andspecifications of TRINITTE.
In the future, we will investigate new applications ofuse, such as special uses that matchuser requirements
and the development of new sizes.
The Precision Equipment Division will work on
supporting the changing situation in which workpieces
are becoming more diverse, such as their increasing
miniaturization and complexity, and achieve stable
and continuous operation for the supply of parts
so that we can continue to contribute towards theautomation of production equipment using robots.