Chassis

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Chassis documentation in PDF form: Datei:Chassis Module.pdf‎



Synopsis

This module is responsible for the various mounting solutions for the lidar, including, but not limited to, mounting on a nacelle, a meteorological tower, the ground, a floating platform, or a mobile structure. The module must contain accelerometers and other sensors that can be interfaced with the Control module in order to adjust for measurement errors due to the movement of the lidar system. In addition to this, it should contain stabilizers and mechanisms for easy and secure installation, and should be operate in a wide range of atmospheric conditions.

Glossary of Terms

There are no specific terms to mention at this time.

Design Requirements

This section includes the objectives and constraints of the Chassis module.

1. The Chassis should operate in a wide range of atmospheric conditions

  a.Relative Humidity of 0 to 100% (1)
  b.Temperatures from -40° to 40° C (1)

2. The Chassis must be easy to install and remove

  a.Rapid removal (1)

3. The Chassis should allow for stable, secure mounting of the system in a wide range of terrains 4. The Chassis should be able to support a weight of up to 50kg

Safety

This section describes the safety concerns of the Chassis module, and suggestions for mitigating any possible risks.

There are two major safety concerns for this module. First, the motors driving the rotation platform should be enclosed so as to prevent injury while the lidar is operating. These motors should not be powerful enough to harm individuals should they become caught in moving parts. Second, heavy lifting attachments must be labeled to indicate weight limits and correct operating procedures.

High Level Overview

This section will discuss the main functions of the Chassis module and its constituent components.

This module is fairly simplistic, containing only a few basic components. The overview of this module is summarized in Figure 1 and its constituent parts are described below. The mount includes the legs of the lidar that allow it to stand on different surfaces. The Motion Compensation helps correct for placement on a moving surface and, finally, the lifting component allows machinery or individuals to attach to the lidar and physically move it.

Chassis System Diagram.jpg

Figure 1: System diagram for Chassis

Low Level Information

This section will discuss the details of the Chassis module, including suggestions that may be implemented to accomplish its roles in the lidar system.

The Chassis module has three main responsibilities in the lidar system, each of which is described below. As can be seen in Figure 1, the main roles of the Chassis module are lifting the lidar, stabilizing it while it is in use, and mounting it securely.

Lifting

Lifting the lidar may be done in two ways: heavy lifting and manual lifting. The former includes bringing the lidar system to the top of a wind turbine for nacelle mounting, where a crane may be used to transport the system to such heights. In this case, an attachment is needed for easily connecting it to a crane and disconnecting it once it has reached its destination. The latter includes transporting the lidar to a ground location, in which an individual or group of individuals may need to carry the system manually. In this case, ergonomic and sturdy handles should be installed on the chassis to maximize comfort for the individuals transporting the system.

Motion Compensation

The chassis should also have motion compensation in order to minimize movement of the lidar system due to external vibrations. On the physical side this should include springs and dampers to stabilize the lidar. This component of the chassis must also include some form of accelerometer or other sensor(s) that can transmit data about the movement of the lidar to the Control module (Internal Controller), which can use this data to reduce errors in wind speed measurements.

Mount

Finally, the chassis module must include capabilities for fast, sturdy, and easy mounting to the platform on which it is being used. This mounting must include the ability to secure the lidar to a surface, a rotating platform to orient the lidar about multiple axes (the number of which depends on the model) and a motor to rotate the lidar about these axes. It is also recommended that the chassis should have a four- or three-legged platform to stand on. Four-legged platforms are beneficial for relatively flat surfaces, while three-legged tripods are beneficial for mounting on rough surfaces or nacelles. In these terrains, adjustment may be needed to ensure that the lidar is level. The four legged model is suggested to be cheaper, and easier to install, as it would include fixed legs that add little height to the system, whereas the tripod is suggested to be a luxury addition, with adjustments for more intensive applications.

Interfaces

Chassis Dependency Map.jpg

Figure 2: Dependency map of Chassis module; details included in Table 1

Figure 2 shows the dependencies of the Chassis Module with the rest of the lidar system. The inputs and outputs are described in detail in Table 1 below. The descriptions are colour coded for ease of reading and transferring from diagram to text.

Inputs Outputs
Power

- Power supply for motors and sensors

Control

- Gyroscopic and accelerometer sensor data is sent to internal controller

Housing

- Physical connections for legs, platforms, and stabilizers

Table 1: Inputs and outputs of Chassis module

Progress

This module is currently in the abstract definition phase and information regarding power as well as specific design (weight, dimensions, components, etc.) needs to be accomplished before prototyping can begin.

Testing

Type description of testing on module here.

Comments

Software and power diagrams should be created as needed.

Chassis module colour (Hex code): #00ff00

Revision History

Description of Work Date Author
Document started 13.07.15 Frank Modruson IV
Added Design Requirements, lifting component, system diagram, interfaces 16.07.15 Frank Modruson IV
Added Safety section, new system diagram, dependency map, updated interfaces to table 30.07.15 Frank Modruson IV
General edits to grammar and style, as well as references added 31.07.15 Joshua Calafato, Katherine Maul, Frank Modruson IV, Alan Yeh
Additions to High Level and Low Level Overviews 31.07.15 Katherine Maul, Joshua Calafato
Added References 01.08.15 Frank Modruson IV
Changed Gyroscopic Stabilizer to Motion Compensation, split Low Level into sections, weight requirement (approximation) 10.08.15 Frank Modruson IV

References

1. Harris, M., Hand, M., & Wright, A. (2006). Lidar for Turbine Control. Retrieved August 1, 2015, from http://www.nrel.gov/wind/pdfs/39154.pdf