# Road Profile

Road profile with varying elevation and friction properties

**Library:**Simscape / Driveline / Tires & Vehicles

## Description

The Road Profile block represents a road profile with varying elevation and friction properties. As a vehicle travels, the axle parameters and the position of the center of gravity (CG) determine the position of the front and rear axles. The block uses the axle positions to compute vehicle angle and, optionally, tire friction coefficients. The block models friction using either Magic Formula or kinetic and static friction coefficients.

### Variables

Use the **Variables** tab to set the priority
and initial target values for the block variables before simulating.
For more information, see Set Priority and Initial Target for Block Variables.

## Ports

### Conserving

`H`

— Horizontal motion

mechanical translational

Conserving port associated with the horizontal motion. Connect to the
**H** port of the Vehicle
Body block.

### Output

`MF`

— Front axle friction coefficients

vector

Physical signal output port for the friction coefficients of the front axle.

The vector contains four elements for the Magic Formula friction model or two elements
for the friction coefficients friction model. Connect to the
**M** port of a front axle Tire (Friction
Parameterized) or Tire (Magic
Formula) block.

This port is visible only when the **Friction
output** parameter is set to one of these values:

**Physical signal Magic Formula coefficients****Physical signal friction coefficients**

`MR`

— Rear axle friction coefficients

vector

Physical signal output port for the friction coefficients of the rear axle.

The vector contains four elements for the Magic Formula friction model or two elements
for the friction coefficients friction model. Connect to the
**M** port of a rear axle Tire (Friction
Parameterized) or Tire (Magic
Formula) block.

#### Dependencies

This port is visible only when the **Friction**
parameter **Friction output** is set to one of
these values:

**Physical signal Magic Formula coefficients****Physical signal friction coefficients**

`beta`

— Vehicle angle

scalar

Physical signal output port for the vehicle angle.

## Parameters

### Main

`Horizontal distance from CG to front axle`

— Distance between CG and front axle

`1.4`

`m`

(default) | positive scalar

Horizontal distance from the center of gravity (CG) to the front axle. Specify the same
value as is specified for the **Horizontal distance from CG to
front axle** parameter of the connected
Vehicle Body block.

`Horizontal distance from CG to rear axle`

— Distance between CG and rear axle

`1.6`

`m`

(default) | positive scalar

Horizontal distance from the center of gravity (CG) to the rear axle. Specify the same
value as is specified for the **Horizontal distance from CG to
rear axle** parameter of the connected
Vehicle Body block.

`Horizontal distance for vertical profile`

— Vertical profile horizontal distance

`[-10, 0, 10]`

`m`

(default) | vector

Table lookup corresponding to the distance that the CG of the vehicle moves relative to
the reference frame *x*-axis. For example the figure
shows a horizontal profile of [-10, 0, 10]. Table lookup extrapolation
is nearest.

`Vertical profile`

— Vertical profile

`[0, 0, .25]`

`m`

(default) | vector

Table lookup corresponding to the distance that the CG of the vehicle moves relative to
the reference frame *y*-axis. For example the figure
shows a vertical profile of [2, 0, 5]. Table lookup extrapolation is
nearest.

### Friction

`Friction output`

— Friction coefficient output type

`None`

(default) | ```
Physical signal Magic Formula
coefficients
```

```
Physical signal friction
coefficients
```

Type of friction coefficient that the block outputs. Select
```
Physical signal Magic Formula
coefficients
```

to vary friction for Tire (Magic
Formula) blocks. Select ```
Physical signal
friction coefficients
```

to vary friction for
Tire (Friction
Parameterized) blocks.

#### Dependencies

Setting this parameter to **Physical signal Magic Formula
coefficients** or **Physical signal friction
coefficients** makes the **MF** and
**MR** ports and associated
**Friction** parameters visible.

`Horizontal distance for friction profile`

— Horizontal distance for friction profile

`[-10, 2, 2.1, 6, 6.1, 10]`

`m`

(default) | vector

Friction profile horizontal distance.

#### Dependencies

This parameter is visible only when the
**Friction** parameter **Friction
output** is set to one of these values:

**Physical signal Magic Formula coefficients****Physical signal friction coefficients**

`Magic Formula coefficients for front axle`

— Front axle Magic Formula coefficients

```
[10, 2, 1, 1; 10, 2, 1, 1; 8, 3, 1, 1; 8, 3,
1, 1; 9, 4, 1, 1; 9, 4, 1, 1]
```

(default) | matrix

Magic Formula coefficients specified as an *n*-by-*4*
matrix, where *n* is the number of points in the vector
specified by the **Horizontal distance for friction
profile** parameter.

#### Dependencies

This parameter is visible only when the
**Friction** parameter **Friction
output** is set to **Physical signal Magic
Formula coefficients**.

`Magic Formula coefficients for rear axle`

— Rear axle Magic Formula coefficients

```
[10, 2, 1, 1; 10, 2, 1, 1; 8, 3, 1, 1; 8, 3,
1, 1; 9, 4, 1, 1; 9, 4, 1, 1]
```

(default) | matrix

Magic Formula coefficients specified as an *n*-by-*4*
matrix, where *n* is the number of points in the vector
specified by the **Horizontal distance for friction
profile** parameter.

#### Dependencies

This parameter is visible only when the
**Friction** parameter **Friction
output** is set to **Physical signal Magic
Formula coefficients**.

`Static and kinetic friction coefficients for front axle`

— Front axle friction coefficients

```
[.9, .7; .9, .7; .7, .5; .7, .5; .8, .6; .8,
.6]
```

(default) | matrix

Front axle static and kinetic friction coefficients specified as an
*n*-by-*2* matrix, where
*n* is the number of points in the vector specified
by the **Horizontal distance for friction profile**
parameter.

#### Dependencies

This parameter is visible only when the
**Friction** parameter **Friction
output** is set to **Physical signal friction
coefficients**.

`Static and kinetic friction coefficients for rear axle`

— Rear axle friction coefficients

```
[.9, .7; .9, .7; .7, .5; .7, .5; .8, .6; .8,
.6]
```

(default) | matrix

Rear axle static and kinetic friction coefficients specified as an
*n*-by-*2* matrix, where
*n* is the number of points in the vector specified
by the **Horizontal distance for friction profile**
parameter.

#### Dependencies

This parameter is visible only when the
**Friction** parameter **Friction
output** is set to **Physical signal friction
coefficients**.

## Extended Capabilities

### C/C++ Code Generation

Generate C and C++ code using Simulink® Coder™.

## Version History

**Introduced in R2019a**

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