**5.1 Remote experimentation of an electrical machine**

The methodology described in the above section is applied to show remote access to the setup of electrical motor located in the IRCCyN laboratory in Nantes France (figure 6), from the CIIDIT-Mechatronic laboratory in Monterrey, Mexico.

The set-up located at IRCCyN is composed of an induction motor, a synchronous motor, inverters, a real time controller board of dSPACE DS1103 and interfaces which allow to measure the position, the angular speed, the currents, the voltages and the torque between the tested machine and the synchronous motor. The motor used in the experiments has the following values: 1.5 kW normal rate power; 1430 rpm nominal angular speed; 220V nominal voltage; 7.5A nominal current; np = 2 number of pole pairs, with the motor nominal parameters: Rs = 1.633 Ohms stator resistance; Rr = 0.93 Ohms rotor resistance; Ls = 0.142H stator self-inductance; Lr = 0.076H rotor self-inductance; Msr = 0.099H mutual inductance; J = 0.0111/rad/s2 inertia (motor and load); fv = 0.0018Nm/rad/s viscous damping coefficient. The experimental sampling time T is equal to 200 s.

Furthermore, this laboratory is equipped with the remote technology described above, and can present several time delays that can appear during any real time experiments and are necessary to analyze:


Web-Based Laboratory Using Multitier Architecture 245

Fig. 7. Remote access by Mexican user.

Fig. 8. Remote experimentation using LogmeIn services.

Fig. 9. Remote images of the induction motor.

Fig. 6. IRCCyN laboratory schema.

These time delays depend on the tele-presence scheme selected. In a telecontrol scheme, the total time T = TI + TC + TS could be high and could affect the stability of the system. Nevertheless, if T = TC + TS is small, then a teleoperation scheme offers an excellent solution in remote experimentation, due to the time delay TI is not considered by the aforementioned reasons (see section 2).

Therefore, the scheme used for remote experimentation is based on teleoperation where the effects of the time delay and uncertain property is not considered in the stability of the system, because the controller and the plant are in the same layer, as shown in figure 2.

In this experiment, the time delays registered are: TI (ping) = 400 mseg. avg., TI (camera) = 3 seg. avg., TI (screen feedback, VNC) = 2 seg. avg., TC < 70 mseg.; TS = 120 seg. (DS1104).

Figure 7 shows a Mexican user, which applies a control algorithm, in order to access the remote laboratory, located in Nantes; France. From the figure 7, we can see *the computer A* showing the images sent by the webcam and the response obtained when the control algorithm is applied to the induction motor, which is transmitted by computer B using Controldesk and Matlab.

Figure 8 and 9 shows the screenshots obtained from this experiment. The first image shows the images given by webcam of the machine (with the sound), the second figure shows the Remote software ControlDesk throughout LogmeIn services.

These time delays depend on the tele-presence scheme selected. In a telecontrol scheme, the total time T = TI + TC + TS could be high and could affect the stability of the system. Nevertheless, if T = TC + TS is small, then a teleoperation scheme offers an excellent solution in remote experimentation, due to the time delay TI is not considered by the

Therefore, the scheme used for remote experimentation is based on teleoperation where the effects of the time delay and uncertain property is not considered in the stability of the system, because the controller and the plant are in the same layer, as shown in figure 2.

In this experiment, the time delays registered are: TI (ping) = 400 mseg. avg., TI (camera) = 3 seg. avg., TI (screen feedback, VNC) = 2 seg. avg., TC < 70 mseg.; TS = 120 seg. (DS1104).

Figure 7 shows a Mexican user, which applies a control algorithm, in order to access the remote laboratory, located in Nantes; France. From the figure 7, we can see *the computer A* showing the images sent by the webcam and the response obtained when the control algorithm is applied to the induction motor, which is transmitted by computer B using

Figure 8 and 9 shows the screenshots obtained from this experiment. The first image shows the images given by webcam of the machine (with the sound), the second figure shows the

Remote software ControlDesk throughout LogmeIn services.

Fig. 6. IRCCyN laboratory schema.

aforementioned reasons (see section 2).

Controldesk and Matlab.

Fig. 7. Remote access by Mexican user.

Fig. 8. Remote experimentation using LogmeIn services.

Fig. 9. Remote images of the induction motor.

Web-Based Laboratory Using Multitier Architecture 247

In the experiment, such a move-and-wait strategy is implemented of initiating control move then waiting to see the response of distant robot: then initiating a corrective move and waiting again to realize the delayed response of the distant system and the cycle repeats

Let us define N(I) to be the number of individual moves initiated by the operator according to the move-and-wait strategy. The number N(I) depends only on the task difficulty and is independent of the delay value according to experiments (Hocayen & Spong, 2006). Consequently, the completion time, t(I), of the certain task can be calculated based on the

( )

*N I*

*i*

=

1

() ( ) ( ) ()

*tI t t t t t NI t t*

Where , , ,, *r mi wi <sup>g</sup> <sup>d</sup> tt t tt* are human`s reaction time, movement times, waiting times after each move, grasping time and delay time introduced into communication channel, respectively.

*r mi wi r d g d*

=+ + + + ++ (1)

until the task is accomplished.

Fig. 10. CIIDIT Laboratory schema.

value N(I) as follows:
