Shanghai Jingte Intelligent Uskin Skin Tactile Sensor Robot

Uskin skin tactile sensor's 3-axis force sensor array is used to realize tactile sensing of robot hands and grippers. XELA tactile sensing array has the advantages of compactness,thinness,softness,durability and less wiring. Uskin sensor arrays are available in 1×1,2×1,2×2,4×4,and 4×6 specifications. It also supports appearance customization.

main feature

1. Digital output

Provides digital output,requiring only a few thin wires and no additional analog-to-digital converters. Provides faster,more accurate measurements while minimizing electrical noise and interference.

2. Soft and durable

This is a soft sensor capable of handling fragile objects without damaging them. Objects of varying sizes,shapes,hardnesses and weights can be reliably grasped and manipulated. The softness also ensures that the sensor is highly resilient to overload,making it very durable.

3. Easy to integrate

XELA offers tactile skin sensors that can be easily integrated for simple adhesive or connection mounting.

XELA Robotics provides the human of touch to robots. By producing patches with integrated sensors capable of sensing 3 axis in each and every sensor included in the skin patch. These patches can be integrated easily into both new and existing robotics thanks to the small size and few attached wires. With our solution the robotic application,such as grippers and robotic hands,can easily what they are gripping or holding. This will give them the of touch similar to that of a human hand when manipulating objects.

Allegro Hand Integration with Curved Fingertips
Integrating uSkin regular sensors and uSkin Curved onto the Allegro Hand provides you with
368 3-axis measurements.
The curved fingertips ensure a natural interation with the grasped object,making it possible
for robots to perform actions as we humans do with our hands.

FEATURES OF ALLEGRO HAND by WONIK Robotics
Lightweight and portable anthropomorphic design
Low-cost dexterous manipulation
Capable of handling a variety of object geometries
Capable of holding up to 5 kg
16 independent torque-controlled joints,4 joints i n each finger

DIGITAL OUTPUT

The digital output provides you with faster,more accurate

measurements with minimal electric noise and interference.

In addition,due to the digital output,only 4 wires are required to

collect all the tactile information.

SOFT & DURABLE

uSkin is a soft sensor capable of handling fragile objects without

damaging them. Objects of different size,shape,hardness,and

weight can be grasped and manipulated reliably.

The softness of uSkin also ensures that the sensor is highly

resilient to overloading,making uSkin very durable.

Introducing Our Newest Model

We provide high-density 3-axis tactile sensing,making it possible to

measure a 3-axis movement,providing with a precise,sensitive,

and overall more reliable tactile data collection.

Our newest uSkin model is: uSkin Curved.

This tactile sensor has 30 individual taxels that can measure 3D

displacement individually. The soft,durable,and curved design allows

for more natural interaction with the object.

FEATURES

Type: Tri-axial Curved Tactile Sensor Module

Taxels: 30

Soft Skin

Fingertip Design

INTEGRATION SERVICE

The uSkin sensors can be integrated into both new and existing

robots.

In addition to providing the tactile sensors,XELA Robotics also

specializes in integrating them into various robot hand and

gripper applications.

HIGH DENSITY 3-AXIS MEASUREMENTS

Each taxel in uSkin sensor mimics a joystick,measuring

X,Y and Z force:

•

Shear forces tangential to the surface

•

Normal force perpendicular to the surface

Providing with a more detailed and accurate data

collection.

Tactile Sensor (XR1944) - Instruction Manual

July 2020

1 General Limitations for using the Sensors

• Applying too high forces or pressures will destroy the sensor module and will void the warranty.

Never apply more than 3 N z-axis force (force applied perpendicular to the sensor’s surface) to one

sensor cell (the XR1922 has 4 sensor cells,for example). Regarding x-axis and y-axis,the sum of

the shear forces has to stay below 15 kPa. These values are higher than the measurement range of the

sensor (given in the datasheet),as the sensor can be overloaded.

Furthermore,apply forces only to the sensor surface,not to the sides of the sensor module.

• As a skin sensor,the contact geometry always inflfluences the measurements. Therefore,we do not

calibrate the sensors,as any calibration would be valid only for the same contact shape. We suggest

that you use machine learning techniques or your algorithms to get various information out of the

sensor measurements,relevant for your application.

• As our sensor uses magnetic fifield changes induced by the skin deformation as its sensing principle,

other magnetic fifields (inc the earth magnetic fifield),nearby magnets,or nearby ferromagnetic

materials can inflfluence the sensor measurements. Also crosstalk between two of our sensor mod

ules is possible. Please confifirm within the inspection period (1 month from receipt of the product)

with your application if those inflfluences are prohibitory for your application. To counteract those

inflfluences,please also consider that a reference sensor could be used.

• Never bend the sensor modules. When you install the sensor modules on your robot,glue them to

a sturdy and flflat surface with thin double-sided sticky tape. Make sure to provide flflat support to the

whole backside of the sensor module.

2 Requirements

To collect data from the sensors,a PC with a USB 2.0 port is required. Both a Windows or Linux PC can be

used,as described in the "Software Manual". However,for the simple procedure to check if your sensors are

connected correctly to your PC,as described in this manual,a Windows PC is used. The software described

in this manual was tested on Windows 7 and Windows 10.

Our sensors work with various CAN-USB converters,as described on our webpage (https://xelarobotics.

com/en/canusb-adapters). This manual (in particular Section 4.2 and 5.1) is based on the software for the

CAN-USB/2 from ESD. The following CAN-USB devices are supported and tested.

• ESD CAN-USB/2 (bus: esd in Windows or socketcan in Linux)

• PEAK USB-CAN (bus: pcan,default channel: CAN_USBBUS1,Linux/ROS only)

• VScom USB-CAN Plus (bus: slcan,Linux/ROS only)

• CANable and CANable Pro (bus: socketcan,Linux/ROS only,with candlelight fifirmware) (Recom

mended only for advanced users knowing CAN DSUB-9 pinout)

The software described in the "Software Manual" is based on Python. However,other programming

guages can be used both for the server (which reads out the sensor data from the CAN bus) and the client

(which uses the sensor data). It is straightforward to use other programming languages for the client,as

they only have to connect to the server. For the server,while we only provide the server in Python,other

environments can be used,as long as they are compatible with the used CAN-USB converter. For example:

• ESD provides API for .NET,C#,Python,VC,Visual Basic,BC,LabVIEW,Linux,etc. Please refer

to ESD website for more information.

2 ©XELA Robotics• Peak System provides API for C#,Python,C,Visual Basic,Linux,etc. Please refer to PEAK System

website for more information.

3 Hardware Introduction

Figure 1: The connection between Sensor Module,Port-A/B cable,the microncontroller,and their respec

tive SDA numbers and taxel numbers. The measurement axis is also shown here.

3.1 Sensor Module

Each Sensor Module has 16 sensing points (taxels) in total. Each taxel measures 3-axis skin deformation.

The sampling rate is 100 Hz. Each measurement has 16-bit (8 Most Signifificant Bit/ MSB and 8 Least

Signifificant Bit/ LSB) resolution per axis. Please see Figure.1 for the taxels’ number,their position,and

their respective SDA .

3.2 Port-A/B cable

The Port-A/B cable is used for connecting 2 Sensor Modules to 1 microcontroller. A label at the Port-A/B’s

end identify which Port a Sensor Module is connected to. Depending on this,the SDA number changes.

When a Port-A/B cable is not used to connect a Sensor Module to a microcontroller,it will be treated as

the Sensor Module is connected via Port-A. In other words,the SDA number of the Sensor Module will be

SDA0 and SDA1.

3.3 Microcontroller

The pre-programmed microcontroller is used to start the communication,confifiguring,and collecting the

data of the Sensor Module. The microcontroller can be connected to the Sensor Module through its 8-pin

port. In the current version of the Sensor Module,2 of the module can be connected to one microcontroller

via the provided Port-A/B cable.

On the microcontroller,there are two 4-pin ports (VDD,D+,D-,GND). One of those ports is for the

communication between the microcontroller and the CAN/USB converter. The other one is for a daisy

chain communication between microcontrollers through a CAN protocol. These ports are interchangeable.

Several microcontrollers with Sensor Modules can be daisy-chained.

3 ©XELA Robotics3.4 ESD CAN/USB Interface

3.4 ESD CAN/USB Interface

This device interfaces a PC with the microcontroller. It is connected to the PC with a serial bus (USB). This

device was developed by ESD and can be purchased separately from https://esd.eu/en/products/can-usb2.

The driver is also available from the given link.

3.5 CAN to DE-9 cable

This cable connects the microcontroller (4-pin connector) to the ESD CAN/USB converter (DE-9 connec

tor). The 4 pin wires are for transmitting data to the ESD CAN/USB interface.

4 Setup & Installation

4.1 Connecting the hardware

1. Plug the 8-pin wires of one Sensor Module’s into a microcontroller. The Port-A/B cable can be used

to connect two Sensor Modules to one microcontroller.

2. Connect the 4-pin connector of the CAN/DE-9 cable to 1 of the 2 4-pin port of the microcontroller.

3. Connect the DE-9 connector of the CAN/DE-9 cable to the CAN/USB Interface.

4. Plug the USB cable of the CAN/USB Interface into any of the USB ports of your PC.

5. Plug the USB power cable of the CAN/DE-9 cable into a PC or USB wall adapter (5V). The power

indicator (blue LED) of the microcontroller should be on.

4.2 Driver and Libraries Installation

4.2.1 ESD CAN/USB driver

After plugging in the USB cable,open the device from the control panel. In the USB section,

make sure that the device is detected as an unknown device. Right click the unknown device and specify

the driver location to the CAN USB Driver folder (...\CAN USB Driver). The driver can be downloaded

4 ©XELA Roboticsfrom the ESD website or can be found inside the installation CD. If it is successful,the unknown device

should turn into "CAN Interface - CAN USB/2" as in Fig. 3.

4.2.2 CAN SDK

Run CAN_SDK.exe from ...\CAN USB driver\CAN_SDK and follow the instructions. This will install the

ESD CAN/USB libraries and sample programs required for the next step.

5 Explanation of CAN ID and CAN message

5.1 CANreal

Here we use CANreal application provided by ESD to make the explanation easy to understand. Run the

CANreal application. The application is installed as part of SDK and can be found by default at C:\Program

Files\ESD\CAN\SDK\bin32\CANreal. Confifigure it as in Fig. 4.

5 ©XELA Robotics5.2 Incoming ID structure

Select a detected CAN/USB device by choosing it from the "Net" drop-down menu. If there is nothing that

can be selected,the device may not be plugged or the driver is not installed properly. Confifigure the "Baud"

to 1000 then click "Start". A Successful connection will lead to an incoming Message as in Fig. 5. At

this point,your PC is ready to run our sample code.

5.2 Incoming ID structure

Each incoming message comes with its ID. The ID represents the number of microcontroller and the

taxel of the Sensor Module connecting to that microcontroller. The meaning of the ID is as shown in Table

• "Microcontroller ID" is pre-defifined. The number can be found on each microcontroller.

• "SDA number" is defifined from whether Port A or Port B of the Port-A/B cable that the Sensor

Module is connected to. If a Sensor Module is connected to Port A,the SDA number will be 0 and 1

depending on the position of the taxel. See Figure 1 for more detail.

• "Taxel Number" is defifined as in Figure 1.

Therefore,the incoming IDs of the taxels on the Sensor Module which is connected to the microcon

troller ID1 via Port A,are as follow.

• SDA 0 Taxel 0 - 3 : 0x001 - 0x031

• SDA 0 Taxel 4 - 7 : 0x041 - 0x071

• SDA 1 Taxel 0 - 3 : 0x101 - 0x131

• SDA 1 Taxel 4 - 7 : 0x141 - 0x171

For the Sensor Module that is connected via Port B of the same microcontroller ID1,the incoming

IDs of the taxels are as follow.

• SDA 2 Taxel 0 - 3 : 0x201 - 0x231

• SDA 2 Taxel 4 - 7 : 0x241 - 0x271

• SDA 3 Taxel 0 - 3 : 0x301 - 0x331

• SDA 3 Taxel 4 - 7 : 0x341 - 0x371

Note that if a Sensor Module is connected directly to a microcontroller without any Port-A/B cable,it will

be treated as connecting to Port A.

5.3 Incoming Message structure

Each incoming message contain 8-byte data. The data compose of 3-axis components of contact

measurement. The structure of the data is as follows.

• 1st byte : Not used

• 2nd byte : X-axis MSB

• 3rd byte : X-axis LSB

• 4th byte : Y-axis MSB

• 5th byte : Y-axis LSB

• 6th byte : Z-axis MSB

• 7th byte : Z-axis LSB

• 8th byte : Not used

By combining the MSB and LSB part of each axis,the 16-bit measurement can be acquired.