Simulation 3D Physics Backhoe

Backhoe physics model in 3D simulation environment

Since R2024b

• 

Libraries:
Offroad Autonomy Library / Simulation 3D

Description

The Simulation 3D Physics Backhoe block provides an interface to implement a backhoe vehicle in the Simulink^® 3D world.

Note

Simulating models with the Simulation 3D Physics Backhoe block requires Simulink 3D Animation™ and the Robotics System Toolbox™ Offroad Autonomy Library support package. For more information about downloading the support package, see Install Robotics System Toolbox Offroad Autonomy Library Support Package.

To use this block, ensure that the Simulation 3D Scene Configuration block is in your model. If you set the Sample time parameter of the Simulation 3D Physics Backhoe block to -1, the block inherits the sample time specified in the Simulation 3D Scene Configuration block. The sample time in the Simulation 3D Scene Configuration block must be set to 0.01 or less to prevent jittering of the backhoe in the 3D visualization environment.

These illustrations show the dimensions and locations of the backhoe asset parameters relative to the coordinate axes, following the yaw(z), pitch(y), roll(x) sequence. The vehicle layout follows Unreal Engine^® co-ordinate system which follows the left-hand rule world coordinate system. For more information, see Coordinate Systems for Unreal Engine Simulation in Robotics System Toolbox.

Ports

Note

This block processes all the input and output values using the right-hand rule world coordinate system. For more information, see Coordinate Systems for Unreal Engine Simulation in Robotics System Toolbox.

Input

Velocity — Move vehicle with velocity input

0 (default) | scalar in the range of [-7.5 ,7.5]

Velocity input to move the backhoe vehicle, specified as a scalar in the range of [-7.5 , 7.5].A positive value moves the vehicle forward, whereas a negative value reverses the direction. Specify the velocity in meters per second (m/s).

To keep the input backhoe velocity steady, the system uses a P controller to internally estimate the required acceleration, taking feedback from the current backhoe velocity.

Data Types: double

Throttle — Normalized input to drive backhoe

0 (default) | scalar in the range of [-1 , 1]

Normalized input to drive the backhoe, specified as a scalar in the range of [-1 , 1]. A positive value moves the vehicle forward, whereas a negative value reverses the direction.

The exact response is characterized by the vehicle powertrain. Maximum torque supported by the block is 200 Newton-meters (Nm) and maximum RPM is 6000.

Dependencies

To enable this port, select the Enable throttle (disable velocity) input signal parameter under Backhoe Inputs.

Data Types: double

SteeringAngle — Direction input to vehicle

0 (default) | scalar in the range of [-0.7854 , 0.7854]

Steering angle input to provide direction to the backhoe vehicle, specified as a scalar in the range of [-0.7854 , 0.7854]​. Specify the steering angle in radians.

As the z axis points vertically upwards,a positive input value executes counterclockwise motion.

Data Types: double

FootBrake — Normalized deceleration torque input

0 (default) | scalar in the range of [0 , 1]

Normalized deceleration torque input to reduce vehicle acceleration, specified as a scalar in the range of [0 , 1]. Maximum strength supported by the block is 200 Newton-meters (Nm).

Dependencies

To enable this port, select the Enable foot brake input signal parameter under Backhoe Inputs.

Data Types: double

FrontBucketAngle — Raise or lower front bucket with angle input

0 (default) | scalar in the range of [-0.6109, 1.5533]

Front bucket angle input to raise front bucket up and lower it, specified as a scalar in the range of [-0.6109, 1.5533]. Specify the front bucket angle in radians.

Dependencies

To enable this port, select the Enable loader frame and front bucket angle input signals parameter under Front Bucket Inputs.

Data Types: double

LoaderFrameAngle — Raise or lower loader frame with angle input

0 (default) | scalar in the range of [-1.3963, 0]

Front loader frame angle input to raise front loader frame up and lower it, specified as a scalar in the range of [-1.3963, 0]. Specify the loader frame angle in radians.

Dependencies

To enable this port, select the Enable loader frame and front bucket angle input signals parameter under Front Bucket Inputs.

Data Types: double

RearBucketAngle — Raise or lower rear bucket with angle input

0 (default) | scalar in the range of [0, 1.5533]

Rear bucket angle input to raise rear bucket up and lower it, specified as a scalar in the range of [0, 1.5533]. Specify the rear bucket angle in radians.

Dependencies

To enable this port, select the Enable swing frame, boom, arm, and rear bucket angle input signals parameter under Rear Bucket Inputs.

Data Types: double

ArmAngle — Raise or lower rear arm with angle input

0.0571 (default) | scalar in the range of [0.0571, 1.5533]

Rear arm angle input to raise rear bucket up and lower it, specified as a scalar in the range of [0.0571, 1.5533]. Specify the arm angle in radians.

Dependencies

To enable this port, select the Enable swing frame, boom, arm, and rear bucket angle input signals parameter under Rear Bucket Inputs.

Data Types: double

BoomAngle — Raise or lower rear boom with angle input

0 (default) | scalar in the range of [-1.5533 , 0]

Rear boom angle input to raise rear boom up and lower it, specified as a scalar in the range of [-1.5533 , 0]. Specify the boom angle in radians.

Dependencies

To enable this port, select the Enable swing frame, boom, arm, and rear bucket angle input signals parameter under Rear Bucket Inputs.

Data Types: double

SwingFrameAngle — Move rear swing left-right with angle input

0 (default) | scalar in the range of [-1.2217, 1.2217]

Rear swing angle input to move rear swing left and right, specified as a scalar in the range of [-1.2217, 1.2217]. Specify the swing frame angle in radians.

Dependencies

To enable this port, select the Enable swing frame, boom, arm, and rear bucket angle input signals parameter under Rear Bucket Inputs.

Data Types: double

Output

BackhoeTranslation — Current ground truth world translation of backhoe

vector

Current ground truth world translation of backhoe, specified as a three-element row vector in the form [x, y , z]. x, y , and z are the translations along the x, y, and z axes, respectively. Units are in meters.

Dependencies

To enable this port, select the Enable ground truth world tranlsation output signal parameter under Backhoe Outputs.

Data Types: double

BackhoeRotation — Current ground truth world rotation of backhoe

vector

Current ground truth world rotation of backhoe, specified as a three-element row vector in the form [yaw, pitch, roll]. yaw, pitch, and roll are the rotations about the z, y, and x axes, respectively. Units are in radians.

Dependencies

To enable this port, select the Enable ground truth world rotation output signal parameter under Backhoe Outputs.

Data Types: double

BackhoeVelocity — Current velocity of backhoe

scalar

Current velocity of the backhoe, specified as a positive or negative scalar value. Unit are meters per second (m/s).

Dependencies

To enable this port, select the Enable velocity output signal parameter under Backhoe Outputs.

Data Types: double

BackhoeAngularVelocity — Current angular velocity of backhoe

[0 0 0] (default) | three-element row vector

Current angular velocity of the backhoe, specified as a three-element row vector in the form [wx, wy, wz]. Unit are radians per second.

Dependencies

To enable this port, select the Enable angular velocity output signal parameter under Backhoe Outputs.

Data Types: double

FrontBucketTranslation — Current ground truth world translation of front bucket

vector

Current ground truth world translation of front bucket, specified as a three-element row vector in the form [x, y , z]. x, y , and z are the translations along the x, y, and z axes, respectively. Units are in meters.

Dependencies

To enable this port, select the Enable front bucket ground truth world translation output signal parameter under Backhoe Outputs.

Data Types: double

FrontBucketRotation — Current ground truth world rotation of front bucket

vector

Current ground truth world rotation of front bucket, specified as a three-element row vector in the form [yaw, pitch, roll]. yaw, pitch, and roll are the rotations about the z, y, and x axes, respectively. Units are in radian.

Dependencies

To enable this port, select the Enable front bucket ground truth world rotation output signal parameter under Backhoe Outputs.

Data Types: double

RearBucketTranslation — Current ground truth world translation of rear bucket

vector

Current ground truth world translation of rear bucket, specified as a three-element row vector, in the form [x, y , z]. x, y , and z are the translations along the x, y, and z axes respectively. Units are in meters.

Dependencies

To enable this port, select the Enable rear bucket ground truth world translation output signal parameter under Backhoe Outputs.

Data Types: double

RearBucketRotation — Current ground truth world rotation of rear bucket

vector

Current ground truth world rotation of rear bucket, specified as a three-element row vector in the form [yaw, pitch, roll]. yaw, pitch, and roll are the rotations about the z, y, and x axes, respectively. Units are in radian.

Dependencies

To enable this port, select the Enable rear bucket ground truth world rotation output signal parameter under Backhoe Outputs.

Data Types: double

CurrentFrontBucketAngle — Current front bucket joint angle

scalar

Current front bucket joint angle, specified as a positive or negative scalar value. Units are in radians.

Dependencies

To enable this port, select the Enable current loader frame and front bucket angle output signals parameter under Front Bucket Outputs.

Data Types: double

CurrentLoaderFrameAngle — Current loader frame joint angle

scalar

Current loader frame joint angle, specified as a negative scalar value. Units are in radians.

Dependencies

To enable this port, select the Enable current loader frame and front bucket angle output signals parameter under Front Bucket Outputs.

Data Types: double

CurrentRearBucketAngle — Current rear bucket joint angle

scalar

Current rear bucket joint angle, specified as a positive scalar value. Units are in radians.

Dependencies

To enable this port, select the Enable current swing frame, boom, arm, and rear bucket angle input signals parameter under Rear Bucket Outputs.

Data Types: double

CurrentArmAngle — Current rear arm joint angle

scalar

Current rear arm joint angle, specified as a positive scalar value. Units are in radians.

Dependencies

To enable this port, select the Enable current swing frame, boom, arm, and rear bucket angle input signals parameter under Rear Bucket Outputs.

Data Types: double

CurrentBoomAngle — Current rear boom joint angle

scalar

Current rear boom joint angle, specified as a negative scalar value. Units are in radians.

Dependencies

To enable this port, select the Enable current swing frame, boom, arm, and rear bucket angle input signals parameter under Rear Bucket Outputs.

Data Types: double

CurrentSwingFrameAngle — Current swing frame joint angle

scalar

Current swing frame joint angle, specified as a positive or negative scalar value. Units are in radians.

Dependencies

To enable this port, select the Enable current swing frame, boom, arm, and rear bucket angle input signals parameter under Rear Bucket Outputs.

Data Types: double

Parameters

To edit block parameters interactively, use the Property Inspector. From the Simulink Toolstrip, on the Simulation tab, in the Prepare gallery, select Property Inspector.

Chassis

Type — Backhoe chassis type

Wheeled Backhoe (default)

Backhoe chassis type, specified as Wheeled Backhoe.

Color — Backhoe color

Yellow (default) | Blue | Orange

Backhoe body color, specified as one of these drop down options:

• Blue

• Yellow

• Orange

Name — Backhoe identifier

string scalar

Backhoe identifier name, specified as a string scalar.

Initial Values

Backhoe Initialization

Initial translation (m) — Initial translation of backhoe vehicle

[0 0 0] (default) | vector

Initial translation of backhoe vehicle, specified as a three-element row vector, in the form [x, y , z]. x, y , and z are the translations along the x, y, and z axes respectively, which uses the right-hand rule world coordinate system. Units are in meters.

Initial rotation (rad) — Initial rotation of backhoe vehicle

[0 0 0] (default) | vector

Initial rotation of backhoe vehicle, specified as a three-element row vector, in the form [yaw, pitch, roll]. yaw, pitch, and roll are the rotations about the z, y, and x axes respectively, which uses the right-hand rule world coordinate system. Units are in radians.

rigidBodyTree Geometry Settings

Set the parameters in this tab to enable the visualization of the rigid body tree geometry in the 3D visualization environment.

Collision Geometry Visualization

Enable collision geometry visualization in 3D scene — Visualize rigid body tree collision geometry in 3D visualization environment

off (default) | on

Select this parameter to visualize rigid body tree collision geometry in the 3D visualization environment.

Collision geometry color — Color of the rigid body tree collision geometry

[0 1 0] (default) | vector

Color of the rigid body tree collision geometry being visualized in the 3D visualization environment, specified as a three-element row vector.

Collision geometry transparency — Transparency of the rigid body tree collision geometry

0.1 (default) | scalar

Transparency of the rigid body tree collision geometry being visualized in the 3D visualization environment, specified as a scalar.

Inputs

Backhoe Inputs

Enable throttle (disable velocity) input signal — Specify throttle to move backhoe at input port

off (default) | on

Select this parameter to disable the velocity input and specify throttle at the input port to move the backhoe vehicle.

Enable foot brake input signal — Specify foot brake at input port

off (default) | on

Specify foot brake torque at the input port to de-accelerate the backhoe vehicle.

Front Bucket Inputs

Enable loader frame and front bucket angle input signals — Specify loader frame and front bucket angle at input port

off (default) | on

Select this parameter to specify the loader frame and front bucket angles at the input port.

Rear Bucket Inputs

Enable swing frame, boom, arm, and rear bucket angle input signals — Specify swing frame, boom, arm, and rear bucket angle at input port

off (default) | on

Select this parameter to specify the swing frame, boom, arm, and rear bucket angle at the input port.

Outputs

Backhoe Outputs

Enable ground truth world tranlsation output signal — Output ground truth world translation of backhoe

off (default) | on

Select this parameter to output ground truth world translation of backhoe at the BackhoeTranslation output port.

Enable ground truth world rotation output signal — Output ground truth world rotation of backhoe

off (default) | on

Select this parameter to output ground truth world rotation of backhoe at the BackhoeRotation output port.

Enable velocity output signal — Output current velocity of backhoe

off (default) | on

Select this parameter to output current velocity of backhoe at the BackhoeVelocity output port.

Enable angular velocity output signal — Output current angular velocity of backhoe

off (default) | on

Select this parameter to output current angular velocity of backhoe at the BackhoeAngularVelocity output port.

Front Bucket Outputs

Enable front bucket ground truth world translation output signal — Output ground truth world translation of front bucket

off (default) | on

Select this parameter to output ground truth world translation of front bucket at the FrontBucketTranslation output port.

Enable front bucket ground truth world rotation output signal — Output ground truth world rotation of front bucket

off (default) | on

Select this parameter to output ground truth world rotation of front bucket at the FrontBucketRotation output port.

Enable current loader frame and front bucket angle output signals — Output current loader frame and front bucket joint angle

off (default) | on

Select this parameter to output current loader frame and front bucket joint angle at the CurrentLoaderFrameAngle and CurrentFrontBucketAngle output ports respectively.

Rear Bucket Outputs

Enable rear bucket ground truth world translation output signal — Output ground truth world translation of rear bucket

off (default) | on

Select this parameter to output ground truth world translation of rear bucket at the RearBucketTranslation output port.

Enable rear bucket ground truth world rotation output signal — Output ground truth world rotation of rear bucket

off (default) | on

Select this parameter to output ground truth world rotation of rear bucket at the RearBucketRotation output port.

Enable current swing frame, boom, arm, and rear bucket angle output signals — Output current swing frame angle and current rear bucket, rear boom and rear arm joint angle

off (default) | on

Set this parameter to output the current swing frame angle and the current rear bucket, rear boom, and rear arm joint angles at the CurrentSwingAngle, CurrentRearBucketAngle, CurrentBoomAngle, and CurrentArmAngle output ports, respectively.

Version History

Introduced in R2024b