**2. Remote robot system with force feedback**

#### **2.1 System configuration**

The configuration of the remote robot system with force feedback is shown in **Figure 1**. The system consists of two terminals called the master terminal and slave terminal. Each terminal consists of two PCs, and the PCs are connected to each other via a switching hub.

At the master terminal, a 3 DoF (Degree of Freedom) haptic interface device (3D Systems Touch [10]) is connected to PC for haptic interface device, and another PC is used for video. At the slave terminal, one of the two PCs is used for a web camera (produced by Microsoft Corp., and video resolution is 1920 × 1080 pixels), and the other PC is used for industrial robot. The industrial robot consists of a 6 DoF robot arm (RV-2F-D by Mitsubishi Electric Corp. [11]), a robot controller (CR750-Q [11]), and a force sensor (1F-FS001-W200 [12]). The force sensor is attached to the surface of the flange of the robot arm. The force sensor is connected to the robot controller via the force interface unit.

#### **2.2 Remote operation**

A user at the master terminal can operate the industrial robot at the slave terminal by using the haptic interface device while watching video (coding scheme:

**59**

interns.

*QoS Control in Remote Robot Operation with Force Feedback*

Motion JPEG, average bit rate: 4.5 Mbps). The default position of the haptic interface device is set to the origin, and the position corresponds to the default position

The master terminal updates the position information, calculates the reaction force, and outputs the reaction force every millisecond. The master terminal also transmits the position information to the slave terminal by User Datagram Protocol (UDP). At the slave terminal, the command information which is based on the position information received from the master terminal is sent to the industrial robot every 3.5 milliseconds by the real-time control function [14]. The force information is also acquired by the real-time control function, and the information is transmit-

The reaction force (m) *Ft* applied to the haptic interface device at time *t* (*t* ³ 1) is

where (s) *Ft*-1 denotes the force received from the slave terminal (note that we use only

The position vector *St* of the industrial robot outputted at the time *t* (*t* ³ 2) is

where *Mt* is the position vector of haptic interface device received from the master terminal at time *t*,*V =M M t tt* ( - -<sup>1</sup> ) is the velocity vector and *V<sup>t</sup>* £ *V*max , and *V*max is the maximum movement velocity. That is, in order to operate the robot arm safely, the maximum movement velocity is limited to *V*max (*V*max = 5 mm/s [13] in this

In this chapter, we handle two types of operation, operation with single remote robot system and that between two remote robot systems. In the latter operation, we deal with two types of work (carry together and hand delivery). In carry together, two industrial robots carry an object together. In hand delivery, an object was hand-

As shown in **Figure 2**, the remote robot system with force feedback is expected

In order to solve the problems of imbalance of medical resources, remote surgery/rehabilitation using the remote robot system with force feedback is an effective method. Also, the system can be used for remote surgery training for medical

3 DoF of force here), and *K*scale is a force scale which is set to 1 in this paper. Furthermore, since the maximum force applied to the haptic interface device is 3.3 N [10], the reaction force is set to 3.3 N when the calculated force is larger

(m s ) ( ) *F F t t* = *K*scale 1- (1)

*SM V tt t* = + - - 1 1 (2)

*DOI: http://dx.doi.org/10.5772/intechopen.97011*

of the industrial robot [13].

ted to the master terminal by UDP.

calculated as follows:

calculated as follows:

delivered between the two industrial robots.

**3. Expected applications**

to be used in various areas.

**3.1 Remote surgery/rehabilitation**

than 3.3 N.

chapter).

**Figure 1.** *Configuration of remote robot system with force feedback.*

*QoS Control in Remote Robot Operation with Force Feedback DOI: http://dx.doi.org/10.5772/intechopen.97011*

Motion JPEG, average bit rate: 4.5 Mbps). The default position of the haptic interface device is set to the origin, and the position corresponds to the default position of the industrial robot [13].

The master terminal updates the position information, calculates the reaction force, and outputs the reaction force every millisecond. The master terminal also transmits the position information to the slave terminal by User Datagram Protocol (UDP). At the slave terminal, the command information which is based on the position information received from the master terminal is sent to the industrial robot every 3.5 milliseconds by the real-time control function [14]. The force information is also acquired by the real-time control function, and the information is transmitted to the master terminal by UDP.

The reaction force (m) *Ft* applied to the haptic interface device at time *t* (*t* ³ 1) is calculated as follows:

$$\mathbf{F}\_t^{(\text{m})} = \mathbf{K}\_{\text{scale}} \mathbf{F}\_{t-1}^{(s)} \tag{1}$$

where (s) *Ft*-1 denotes the force received from the slave terminal (note that we use only 3 DoF of force here), and *K*scale is a force scale which is set to 1 in this paper. Furthermore, since the maximum force applied to the haptic interface device is 3.3 N [10], the reaction force is set to 3.3 N when the calculated force is larger than 3.3 N.

The position vector *St* of the industrial robot outputted at the time *t* (*t* ³ 2) is calculated as follows:

$$\mathbf{S}\_{t} = \mathbf{M}\_{t-1} + \mathbf{V}\_{t-1} \tag{2}$$

where *Mt* is the position vector of haptic interface device received from the master terminal at time *t*,*V =M M t tt* ( - -<sup>1</sup> ) is the velocity vector and *V<sup>t</sup>* £ *V*max , and *V*max is the maximum movement velocity. That is, in order to operate the robot arm safely, the maximum movement velocity is limited to *V*max (*V*max = 5 mm/s [13] in this

chapter).

*Robotics Software Design and Engineering*

We also introduce our remote robot system with force feedback which we constructed to study the QoS control and stabilization control by experiment. In the system, a user operates a remote industrial robot with a force sensor by using a local haptic interface device while monitoring the robot operation. We handle two types of operation; operation with a single remote robot system and that between two remote robot systems. We explain several types of QoS control which we have

In this chapter, first, we explain the remote robot system with force feedback in Section 2. Next, we introduce expected applications of the remote robot system with force feedback in Section 3. Then, we outline the problems to be solved for the applications in Section 4 and describe the QoS control which is used to solve the deterioration problems owing to the network delay, delay jitter, and packet loss in Section 5. Finally, we discuss the challenges and future directions of QoS control in

The configuration of the remote robot system with force feedback is shown in **Figure 1**. The system consists of two terminals called the master terminal and slave terminal. Each terminal consists of two PCs, and the PCs are connected to each

At the master terminal, a 3 DoF (Degree of Freedom) haptic interface device (3D Systems Touch [10]) is connected to PC for haptic interface device, and another PC is used for video. At the slave terminal, one of the two PCs is used for a web camera (produced by Microsoft Corp., and video resolution is 1920 × 1080 pixels), and the other PC is used for industrial robot. The industrial robot consists of a 6 DoF robot arm (RV-2F-D by Mitsubishi Electric Corp. [11]), a robot controller (CR750-Q [11]), and a force sensor (1F-FS001-W200 [12]). The force sensor is attached to the surface of the flange of the robot arm. The force sensor is connected to the robot

A user at the master terminal can operate the industrial robot at the slave terminal by using the haptic interface device while watching video (coding scheme:

proposed so far for remote robot operation with force feedback.

Section 6 and conclude the chapter in Section 7.

**2. Remote robot system with force feedback**

**2.1 System configuration**

other via a switching hub.

**2.2 Remote operation**

controller via the force interface unit.

*Configuration of remote robot system with force feedback.*

**58**

**Figure 1.**

In this chapter, we handle two types of operation, operation with single remote robot system and that between two remote robot systems. In the latter operation, we deal with two types of work (carry together and hand delivery). In carry together, two industrial robots carry an object together. In hand delivery, an object was handdelivered between the two industrial robots.
