**6. Design of the Quadcopter with Dual-Head Electromagnetic Propulsion Devices**

The origin of the science of electromagnetic propulsion (EMP) does not fall on any individual, group or institution, but many investigators have found enormous applications in multidisciplinary areas. The principle of EMP is well known, as it accelerates a body using a streaming electrical current, either to charge a field or oppose a magnetic field for the propulsion application. Recently, V.R.Sanal Kumar et al., [36–41] designed an innovative dual-head electromagnetic propulsion and energy conversion system for planet landers and other various industrial applications. The dual-head electromagnetic (DHEM) energy conversion system is found unique for the soft landing of landers on any planet with a variable density atmosphere [39]. The quadcopter design, presented in this paper, is an offshoot of the above-mentioned DHEM energy conversion system developed for planet landers [39–41]. In this study, we demonstrated the capability of a new generation quadcopter UAV integrated with four dual-head EMP devices to spin the rotors with variable speeds and generate the desired lift force in the desired direction in any atmosphere, and further continuously steer the drone for planet surveillance. The uninterrupted exploration of the drone is achieved using the reciprocating moment of a magnetic piston facilitated with each EMP device with a solar-powered polarity changer timing circuit (PCTC) along with a laser-based timing circuit (LBTC) for redundancy during the night zone [36]. A dual-head EMP device is capable of generating an uninterrupted propulsive force for spinning the UAV rotors using a connecting rod and crankshaft mechanism by creating a reciprocating moment of the magnetic piston in a vacuum cylinder by varying the polarity of magnets

for attraction and repulsion. Figure 13a shows the experimental qualification test setup of a dual-head EMP device. Figure 13b shows the physical model of the quadcopter UAV with the dual-head EMP devices. Figure 13c shows the design details of the electromagnetic head (EMH).Figure 14 shows the idealized physical model of an EMP device for creating variable spinning speeds for the UAV rotors for flying in a variable density environment without any lift loss. Figure 15 shows the geometric layout of the pin location (A) of the magnetic piston, the crankpin location (B), and the crank center (C).

(**a**) Experimental qualification test setup of the dualȬhead electromagnetic propulsion (EMP) device

(**b**) Quadcopter UAV with EMP devices

(**c**) Design details of the electromagnetic head (EMH)

**Figure 13.** (**a**–**c**) Ground testing and design details of the quadcopter unmanned aerial vehicle (UAV) with dual-head EMP devices.

**Figure 14.** An idealized physical model of a dual-head EMP device for the UAV.

**Figure 15.** Geometric layout of the EMP device with a crankpin.

The basic equation of the reciprocating magnetic piston system considered in Figure 14 is obtained as,

$$m\_p \frac{d^2 \mathbf{x}\_p}{dt^2} - \frac{\mu q\_1 q\_2}{4\pi \,\mathbf{x}^2 \boldsymbol{p}} - \frac{\mu q\_2 q\_3}{4\pi \left(L - T - \mathbf{x}\_p\right)^2} = 0\tag{1}$$

$$\frac{d^2\mathbf{x}\_p}{dt^2} = \frac{\mu}{4\pi\,m\_p} \left[ \frac{q\_1 q\_2}{\mathbf{x}\_p^2} + \frac{q\_2 q\_3}{\left(L - T - \mathbf{x}\_p\right)^2} \right] \tag{2}$$

where q1, q2, and q3 are magnetic pole strength (see Figure 14), mp is the mass of the magnetic piston, and μ is the permeability.

From Figure 15, the angular velocity of the crankshaft (ω) of the EMP device can be obtained using Equation (3) as follows:

$$\left| \frac{d\mathbf{x}\_p}{dt} + \left| \sin \theta + \frac{\sin 2\theta}{2\sqrt{\left(\frac{l}{r}\right)^2 - \sin^2 \theta}} \right| \text{o } r = 0 \tag{3}$$

The acceleration of the magnetic piston (*dv*/*dt*) can be obtained from Equation (4), as given below:

$$
\left| \frac{dv}{dt} + r \,\alpha^2 \right| \cos \theta + \frac{\left(\frac{l}{r}\right)^2 \cos 2\theta + \sin^4 \theta}{\left(\left(\frac{l}{r}\right)^2 - \sin^2 \theta\right)^{3/2}} \right| = 0 \tag{4}
$$

where r is the crank radius, *l* is the rod length, θ is the crank angle from the top dead center, xp the axial position of the magnetic piston pin, t is the time, and v is the velocity of the magnetic piston (dxp/dt), which is obtained from Equation (3).

#### *Mixed Reality Simulation with Dual-Head EMP Devices to Control the Quadcopter in Space*

A literature review revealed that an autonomous rotorcraft is suitable for planets with an atmosphere, including Mars and Venus [4,36–38]. In this paper, we present the MR simulation with dual-head EMP devices for controlling the quadcopter during a space mission. Figure 16 shows the overview of the MR simulation technique with an EMP device to control the quadcopter in space. A GCS on Earth can communicate and control its device on any planet using the telemetry system. We developed an EMP device to control a quadcopter for a space mission based on the feedback system on atmospheric properties to the PCTC/LBTC controlled dual-head EMP devices. To control the EMP device from the GCS on Earth, we need a clear view and real-time performance of the space quadcopter. Therefore, here, we integrated our developed MR simulation technique with the GCS on Earth, then, using our MR simulation, we can see the clear view and real-time performance of the space quadcopter on our simulation platform (X-Plane). This preliminary study provides information for a real-time experiment with space agencies during the forthcoming planetary missions.

**Figure 16.** Overview of the mixed reality simulation for the quadcopter space activates using a dual-head EMP device.
