Design and Simulation of Electric Street Sweeper in Solidworks

Pradeep
updated on May 16, 2020, 11:55am IST

OBJECTIVE:

 

This is final Individual project report on Ultimate Solidworks course about ideation, design and modelling of Electrical Street Sweeping vehicle in Solidworks. The main aim of this project is to understand the development of design models from concept phase to final simulation phase ,to understand the various challenges in creating a model in a 3D design software and how to represent as a final working model through various design features in Solidworks.





EXECUTIVE SUMMARY

 

This report runs through ideation phase where the theme of the project is developed through a detailed literature study of various successful design models in this topic and goes through the design stage where the raw idea is converted to 3D CAD models through solid modelling and surface modelling techniques in Solidworks and how the parts were sketched and developed using various features and tools in Solidworks. The third stage explains the assembly phase and final phase explains about the simulation and rendering stage of the models .

 

IDEATION:

 

IDEATION STAGE 

Solid waste management is a thing being tackled by every developing countries and it this field India is thriving to develop to make the country clean and prosperous. There has been lot of ideas proposed and implemented to this date but the factor of less emission, sustainable and highly efficient is always eluded. This is one major driving factor in developing the ideation about this project. The next huge factor is the method of designing a vehicle which involves lot of challenging engineering aspects to be considered. Based on these  ideas , Electric Street Sweeping Vehicle is proposed and selected as model for this project. There are lot of design improvisations need in styling and working models hence this would pave a great opportunity to inculcate some of the design techniques in Solidworks through pragmatic approach.




        FIg.1) Dulevo D Zero EV Model for Street Sweeper 



WORKING MODEL

 

Ø  This electrical model uses induction motor with Inverter and transmission system for the vehicle and Mechanical suction type with Cleaning Brushes and a Land rover at the bottom to pick up the debris. 

Ø  The picked up waste is carried to the garbage bin and dumped. There is filter in the tank that separates the waste and the air is let out. This bin can be lifted and disposed when it is full using hydraulic cylinder 

Ø  The Brushes are attached  to the front bumper and can be translated  from left  to right end to give high maneuverability and clean inaccessible areas while the car is in motion.

 

GEOMETRIC DIMEMSION

The whole project is modeled using conceptualize dimensions without using any sketch picture and blueprints. The rough dimensions were obtained from the Dulevo D zero Electric Model and the parts to be modeled are sketched based on suitable dimensions. In this way product development and part based modeling knowledge were enhanced.


                                                             Fig 2)  Dimensions of Electric Street Sweeper 



 

PART MODELLING 

 

This is the second phase of the project. From the Ideation images a concept sketch is developed and the parts modeled for Electric Street Sweeper is derived. The parts were developed through solid feature based modeling and surface modeling through a direct and intuitive graphical manipulation. The parts to be modeled are given below the table.





PARTS

No of Units

Total Design Hours

Chassis

1

30 min

Electric Unit

1

1 hr

Battery module

1

30min

Rear Cabin

1

45 min

Front Cabin

1

1 hr

Cabin Interior

1

1 hr

Front Frame

1

45 min

Sweeping Arm

2

2 hr

Rotating Sweeper

2

15 min

Vacuum Rover

1

30min

Dump Bin

1

1 hr

Hydraulic Cylinder 

1

1hr

Wheels

4

30 min



CHASSIS:

Chassis forms the base of the model and also supporting frame for mounting various parts of the vehicle. 

It has three main parts

    • Drive Train 
    • Wheel Mounting Frame
    • Overhang Front Frame
  •  

Features Involved:

    • Sketch 
    • Offset Entities
    • Solid Extrude
    • Revolve Extrude
    • Extrude Cut
    • Mirror Feature
    • Fillet 
    • Chamfer
  •  

Procedure

Ø  A 2D sketch is created in Top Plane using 2D Sketch Entities and extruded to desired length. Extrude Feature converts the 2D sketch to 3D model.

Ø  For Drive Train and Shaft 2D sketch is created in one plane and revolved along the centreline of the shaft.

Ø  Finally the front overhang is modelled and mirrored along the centre plane.

Ø  Suitable fillet and chamfer are applied along the sharp edges.





 



ELECTRIC ENGINE UNIT

The Electric engine is the prime mover of the vehicle and basically has three main parts

  • Induction Motor 
  • Inverter Unit
  • Open Differential Unit.

 

The Electric Engine is an AC Induction motor that has two parts a stator and rotor.

 

Stator receives 3 phase power input and this produces  Alternating magnetic Field  in the coil  which induces the Rotor coil to rotating motion . This robot and powerful system provides speed depending upon the  frequency of AC Power supply hence by varying the input of AC power the speed of the rotor is varied accordingly. This provides easy and reliable speed control of vehicle with a wide range of RPM.

 

Inverter is brain of the electric vehicle which converts the DC power from BMS and provides the AC power input to the motor and by varying the amplitude of AC Power, motor power output can be varied. 

 

The Drive Train has differential system that translates the power to the drive wheel and this is centred between the inverter and motor and by varying the power phase of AC both forward and reverse motion is achieved. Hence it can be directly attached to the drive train thus efficient speed reduction and torque multiplication can be achieved. 

 

Feature Involved:

·        Extrude Boss

·        Revolve

·        Revolve Cut

·        Cut Extrude

·        Fill Pattern 

·        Circular Pattern 

·        Mirror

·        Fillet





Procedure

Ø  A 2D Sketch is used to revolve as circular solid model using Revolve Extrude and the inside surface is made as cavity using Shell command.

Ø  The Fins around the revolved body are done through circular pattern and rotor and stator are designed through Revolved Cut and Revolve Boss 

Ø  Finally a Central Drive Shaft is designed and attached to the Drive Train 

Ø  The Inverter is designed adjacent to the motor using Revolve Boss and the model is connected with motor by up to next extruded option from the surface of the inverter.

 



 

BATTERY MODULE

 

The Battery is the source for the prime mover and Lithium ion cells are chosen as a battery source. The Cells re arranged in series and parallel and has different blocks. This allows easy replacement and maintenance.

Features Involved

·        Extrude Boss

·        Extrude Thin

·        Surface Offset

·        Projected Curves

·        Solid Sweep

·        Fillet

Procedure

Ø  The Battery module is designed flat and stays along the chassis which will improve the stability of the vehicle 

Ø  The Battery stay is extruded along the top plane and the solid body divided into sections to  individual battery modules.

Ø  Surface Offset is applied along the face and the surface extruded along the top plane.

Ø  The Connection to the Inverter is achieved through projected curves and solid sweep.



FRONT CABIN

The Front cabin is placed over the front overhang of the chassis.. This part has three subassemblies

·        Cabin Structure

·        Cabin Interior

·        Front Frame

CABIN STRUCTURE

The Front side of the cabin is designed to have less blind spot and great observance angle for the driver. The parts designed are

·        Side Window

·        Front Mirror

·        Side Mirror

·        Safety Lights

·        Wiper Reinforcements

Feature Involved

·        Extrude Boss

·        Cut Extrude

·        Shell

·        Mirror

·        Revolve Extrude

·        Surface Loft

·        Linear pattern

·        Sweep Solid

·        Projected Curve

·        Dome

·        Chamfer

·        Fillet

·        Split Line

Procedure

Ø  The Cabin is designed along one plane using solid modeling features and mirrored by the plane to other side.

Ø  The Front window and side window reinforcements are created using cut extrude.

Ø  Side mirror and Top mirror are modeled through project curves and solid swept using circular profile

Ø  Surface Modeling features like surface loft were used for the mirror appearances.

Ø  Wiper is designed along the front face of surface loft and fixtures are given in the top

Ø  Finally the safety lights are designed on the top of the structure using revolve boss.

Ø  Suitable appearance were given.




CABIN INTERIOR

The Interior is designed with two seats, steering wheel and controllers. The Interior space is wide and has good operating space for the Driver and pinion with controllers.

Feature Involved

·        Boss Extrude

·        Surface Offset

·        Mirror

·        Solid Sweep

·        Extrude Cut

·        Fillet

·        Chamfer




FRONT FRAME

The Front frame is a truss assembly that forms the bottom part of the Cabin structure. The parts designed are

·        Fender

·        Step

·        Front Head Lamp

·        Front Name Plate

This protects the cabin from unwanted sills and dust from the Front tire and keeps the Front cabin intact.

Feature Involved

·        Extrude Boss

·        Projected Curve

·        Solid Sweep

·        Surface Loft

·        Dome

·        Mirror

·        Fillet

·        Chamfer




REAR CABIN

Ø  This part is mounted over the rear overhand of the chassis and houses other parts of the vehicle such as hydraulic cylinder, Dump Bin.

Ø  The Rear Cabin also protects the foreign particles from the rear wheel entering into the crumple zone.

Ø  The Battery unit is also mounted on the base of the cabin and has cooling vent that lets out heat from the Battery Coolant System. 

Features Involved

·        Extruded Boss

·        Extruded Cut

·        Mirror

·        Fillet

·        Linear Pattern




DUMP BIN

Ø  This is one of the important parts involved in the cleaning process. The wastes that are picked through various sweeping units are dumped and stored. 

Ø  The Front part of the bin has mounting space for the Mechanical Suction Unit. There is also air filter that particulates clean air and vent it out through the cooling fin at the top.

Ø  Debris is loaded from above into the waste container, thus optimising the vehicle's load capacity

Ø  Once lifted by the central cylindrical brush, dust is sucked up and retained in the waste container thanks to the depression created in said container, by two high flow and head suction valves

Ø  This particular fabric filtering system also retains the finest of particles and completes the sweeping cycle, while guaranteeing the re-emission of only clean air into the environment

  • Ø

Features Involved

·        Extrude Boss

·        Revolve Boss

·        Extrude Cut

·        Shell

·        Projected Curve

·        Solid Sweep

·        Linear Pattern

·        Mirror

·        Split Line




HYDRAULIC CYLINDER

The Cylinder with push rods is designed that lifts the dump bin when the waste collection is completed and can be disposed to the skip. This will be mounted in the rear cabin and has following parts

·        Hydraulic Base

·        Pin

·        Hydraulic Cylinder

·        Bottom Push Rod

·        Middle Rod

·        Top Push Rod

Features Involved

·        Revolve

·        Boss Extrude

·        Cut Extrude

·        Mirror

·        Fillet

·        Chamfer


SWEEPING UNIT

Ø  These are set of parts that perform core working model to this vehicle and the components involved are

·        Front Sweeping Arm

·        Rotating Sweeper

·        Ground Vacuum Rover

 

Ø  The wastes from the ground are picked by these components by the suction force created. The size of these units were designed in such way that provides wide range of  cleaning area through the movement of the vehicle and has high maneuverability.

Ø  Dirt is mechanically collected by side brushes which channel debris to the center of the machine

 

Ø  The vacuum rover attached to front overhang of the chassis picks up the remaining waste left out by the side brush

 

It is launched at a high speed onto a vertical conveyor by the central cylindrical brush.

 

FRONT SWEEPING ARM

 

The two front arms are attached to the Shaft on front overhang chassis. The front arm is designed to have movements that maneuvers along various direction. The Main Parts involved in Sweeping arm are

 

·        Base Loader

·        V Shaft Link

·        Piston Rods

·        Cylinder

·        Front Gripper

 

This Complex Solid Model has various fixture designs that articulate fine physical arm movements that are controlled in different directions.

 

Features Involved

 

·        Extrude Boss

·        Revolve Boss

·        Extrude cut

·        Mirror

·        Projected Curve

·        Composite Curve

·        Solid Sweep

·        Fillet

 

ROTATING SWEEPER

 

The Sweeper has Ground Brush and rotates to pick up wastes. There is stepper motor at the top and water jet nozzle that sprays atomized water spay after cleaning in roads.

 

Features Involved

·        Revolve

·        Shell

·        Circular Pattern

·        Extrude Boss

·        Extrude Cut

·        Mirror

 

VACUUM ROVER

 

Vacuum rover picks up the waste running along the vehicle and lowered to the ground level using the vertical swing bars. There is a rover that runs on along the ground which houses the vacuum unit that channel the debris to the suction unit. The end pipe is attached to the filetr unit at the front of storage unit.

Features Involved

  • ·        Boss Extrude
  • ·        Shell
  • ·        Loft
  • ·        Curve
  • ·        Sweep
  • ·        Cut Extrude
  • ·        Mirror




WHEEL



Wheel has four Main Parts

Ø  Rim

Ø  Tyre

Ø  Brake Callipers

Ø  Disc 

 

Features Involved 

·        Revolve Extrude

·        Revolve Cut 

·        Linear Pattern 

·        Circular Pattern 

·        Fillet 

·        Chamfer 

Procedure 

Ø  A sketch is created based on the revolve axis generator and revolved  around the axis. 

Ø  The part is cut in the centre to facilitate easy mounting to the Chassis.

Ø  The Tyre is revolved around the revolve axis and suitable extrude and cuts were made to protrude from the face and have a rough appearance 

Ø  Rim and Caliper are designed through convert , offset entities and trim entities. Linear pattern were applied to cut out parts along the rim and finally suitable appearance were given.