**2. Creating a simulation**

extender for a hybrid vehicle architecture (state of charge trajectory estimation) [3]; it is used as a validation of a controller for variable steering ratio of a front steering system, tested on a virtual road for driving comfort improvement [4]; it is used for solving challenging problems such as wheel slip control for electric powertrain vehicles, for anti‐lock brake and traction control functional validation (hardware‐in‐the‐loop (HIL) using IPG CarMaker coupled with dSPACE) [5] and complex hardware‐in‐the‐loop system (MATLAB Simulink model coupled with IPG CarMaker multibody vehicle model, dSPACE electronic control unit, and a real

friction brake unit) for brake friction optimization and lower energy consumption [6].

ACC (Adaptive Cruise Control), or other user‐modelled systems.

CarMaker and used as the road or track during simulation.

virtual driver, there are two approaches in CarMaker:

load post‐simulation data, plot, and export results;

following two methods:

2 2 Modeling and Simulation for Electric Vehicle Applications

should do.

environment.

run on a host computer, namely:

Using this knowledge, it is possible to simulate any vehicle in IPG CarMaker, as long as the user knows all the necessary data. The same behaviour can be simulated for any vehicle, on the same road, with the same manoeuvres, just by changing the vehicle properties. The vehicle contains all components from the real vehicle, such as powertrain, chassis, tires, brakes, but also controllers, such as ABS (Anti-Lock Braking System), ESP (Electronic Stability Program),

After defining the virtual vehicle, the user must characterize the road, that is a digitized or computer‐modelled representation of the real road (usual road, track, or course), which simulates the road and it is generated for testing. CarMaker can generate the road using the

**•** An easy method that combines individual road segments, such as straights and curves, to form a continuous road, where all the parameters interconnect. For each segment, the user can define all the data such as angle, slope, pitch, friction coefficient, length, and width.

**•** The second method involves an existing road file (already digitized data), generated by a direct measurement from a GPS device, Google Earth, or other. The file can be opened by

The third step is defining the virtual driver, which simulates the actions of a real driver. All the parameters would normally be controlled by a real driver, such as turning/steering or operating the gas, brake and clutch pedals, shifting gears (for manual transmission). For the

**•** A simply controlled driver, for which the user can specify at each step what the virtual driver

**•** An IPG driver, a smart‐controlled driver, which tries to maintain the given trajectory and operate within specified limits. As an example, the reaction time can be modified.

Altogether, the virtual vehicle, the virtual driver, and the virtual road form the virtual vehicle

CarMaker also has the CIT (CarMaker interface toolbox) that consists of a number of tools that

**•** IPG control—it is a visualization and analysis tool that can monitor quantities in real‐time,

Creating a simulation involves using the CIT to create the desired model of the real situation that needs to be simulated, choosing the vehicle (with all its properties), the driver, the road, the manoeuvres and the load (**Figure 1**).

**Figure 1.** IPG CarMaker main window.

Before actually starting the simulation, the Instruments window should be activated (**Fig‐ ure 2**), the IPGMovie window to visualize the status in real time (or faster) and more impor‐ tantly (**Figure 3**), and the IPG Control Data window to observe the evolution of certain parameters and save results.

**Figure 2.** Instruments window—IPG CarMaker.

**Figure 3.** IPGMovie window.

In order to emphasize the influence of the battery on the E‐motor power consumption, several simulations were made where the variables are the battery pack power, which leads to a different current, but the same voltage, and most importantly a different mass, as given in **Table 1**.


**Table 1.** Properties of the used batteries.

Before actually starting the simulation, the Instruments window should be activated (**Fig‐ ure 2**), the IPGMovie window to visualize the status in real time (or faster) and more impor‐ tantly (**Figure 3**), and the IPG Control Data window to observe the evolution of certain

parameters and save results.

4 4 Modeling and Simulation for Electric Vehicle Applications

**Figure 2.** Instruments window—IPG CarMaker.

**Figure 3.** IPGMovie window.

Also, to monitor the energy consumption and the current on the same vehicle with the same load, a different state of charge was used for each battery pack.

When creating a desired vehicle in IPG CarMaker, several sets of data must be set so that the simulation is as close as possible to the real vehicle, with as few approximations as possible.

**Figure 4** shows the vehicle body in the vehicle data set: in this, a flexible body is used, where the masses of the two bodies are introduced and placed in an x‐y‐z coordinate system. The joint is also defined, which implies that the properties of the stiffness (torsion and bending), damping and occurring amplifications must be defined as well.


**Figure 4.** Vehicle data set—vehicle body menu.

After the properties of the vehicle body are done, the next required input is the vehicle bodies (**Figure 5**), where the required fields are moments of inertia for all wheel carriers, for all the wheels, placements of the wheels, hitch position if required and, if any, trim loads. In this case, there are no trim loads.


**Figure 5.** Vehicle data set—bodies menu.

Since it is an electric car, no internal combustion engine was input (**Figure 6**). This feature can be used if the simulation requires a hybrid vehicle or a classic vehicle.


**Figure 6.** Vehicle data set—engine menu.

When simulating an electric vehicle, after introducing the required data for suspension, steering, tires, and brakes, the powertrain data are extremely important: in the general submenu, the number of electric motors is selected—in this case, one electric motor (**Figure 7**).


**Figure 7.** Vehicle data set—powertrain—general menu.

After the properties of the vehicle body are done, the next required input is the vehicle bodies (**Figure 5**), where the required fields are moments of inertia for all wheel carriers, for all the wheels, placements of the wheels, hitch position if required and, if any, trim loads. In this case,

Since it is an electric car, no internal combustion engine was input (**Figure 6**). This feature can

be used if the simulation requires a hybrid vehicle or a classic vehicle.

there are no trim loads.

6 6 Modeling and Simulation for Electric Vehicle Applications

**Figure 5.** Vehicle data set—bodies menu.

**Figure 6.** Vehicle data set—engine menu.

In the second submenu, drive source, the general data are introduced such as moment of inertia for the electric motor, ratio, build‐up time, friction coefficient, and voltage level (**Figure 8**), but also the torque (as a characteristic value) for both cases of the electric motor (motor or generator), as shown in **Figure 9**, and the efficiencies of the electric motor in both cases (**Figure 10**).


**Figure 8.** Vehicle data set—powertrain—drive source—general menu.


**Figure 9.** Vehicle data set—powertrain—drive source—torque menu.


**Figure 10.** Vehicle data set—powertrain—drive source—efficiency menu.

The next input is the driveline: the rear drive option was selected by this, with no external torque (**Figure 11**), because it is not the case since there is no external torque to the differential or wheels.


**Figure 11.** Vehicle data set—powertrain—driveline menu.

**Figure 9.** Vehicle data set—powertrain—drive source—torque menu.

8 8 Modeling and Simulation for Electric Vehicle Applications

**Figure 10.** Vehicle data set—powertrain—drive source—efficiency menu.

or wheels.

The next input is the driveline: the rear drive option was selected by this, with no external torque (**Figure 11**), because it is not the case since there is no external torque to the differential For the control unit, first the powertrain control is set to electrical, the engine start with button and not key, and the desired input for the body control unit (BCU), motor control unit (MCU), and traction control unit (TCU), as shown in **Figure 12**.


**Figure 12.** Vehicle data set—powertrain—control unit menu.

For the electric vehicle, the power supply is of most importance: low voltage, high voltage or both low voltage and high voltage can be selected; in this case, low and high voltages were selected with no auxiliary consumer for neither low nor high voltage (**Figure 13**).


**Figure 13.** Vehicle data set—powertrain—power supply—general menu.

In the low voltage set‐up menu, the main data regarding the LV battery can be introduced, such as capacity, idle voltage, initial state of charge (ISOC), minimum and maximum state of charge, capacities and resistances of the battery (**Figure 14**).

For the high‐voltage battery, the current state (as on the real vehicle) is inserted, a battery with the capacity of 210 Ah, 85 kW of power, idle voltage of 400 V, and the specific resistances and capacities of the battery (**Figure 15**).


**Figure 14.** Input data for the low‐voltage battery.


**Figure 15.** High‐voltage battery input data.

**Figure 13.** Vehicle data set—powertrain—power supply—general menu.

charge, capacities and resistances of the battery (**Figure 14**).

capacities of the battery (**Figure 15**).

1010 Modeling and Simulation for Electric Vehicle Applications

**Figure 14.** Input data for the low‐voltage battery.

In the low voltage set‐up menu, the main data regarding the LV battery can be introduced, such as capacity, idle voltage, initial state of charge (ISOC), minimum and maximum state of

For the high‐voltage battery, the current state (as on the real vehicle) is inserted, a battery with the capacity of 210 Ah, 85 kW of power, idle voltage of 400 V, and the specific resistances and In the miscellaneous menu, the vehicle graphics and the movie geometry (in order to create a proper video in real time of the desired vehicle: Tesla Model S) were selected (**Figure 16**).

After the vehicle is ready, the input for the road follows (**Figure 17**) where the driver must maintain a constant speed and the manoeuvres are just to follow the given road.


**Figure 16.** Miscellaneous input for the Tesla Model S model.

**Figure 17.** Road generated for the simulation.
