Real Time Problems faced in the Multi Function Displays of Cars

Research Area: Multicore for Real-time Embedded Applications
Authors: Saikiran Kannan, Vijay h, krishnamaraju, mohan d
Faculty mentor: Mrs.ajina
Name of the Institution: Sir M Visvesveraya Institute Of Technology

Abstract:

A Multi-function display (MFD) is a small screen (TFT, DOT MATRIX or LCD) in any

Vehicle [cars here] surrounded by multiple buttons that can be used to display

Information to the Driver in numerous configurable ways.

MFD's are part of the digital era of modern cars. The advantage of an MFD over

Analog Display is that an MFD does not consume much space in the vehicle. All

Information is displayed on the MFD screens.

Many MFD's display the navigation route, speedometer, fuel rate, moving map,

Weather radar, and traffic Information all on the same screen. One way of making

Information situation-based is to use TFT displays.

Like no other type of display, these liquid crystal screens offer a high level of visual

Quality, flexibility and configurability.

An MFD works with the help of CAN (controller area network) which synchronizes all

The communications between the multiple devices in a car. An MFD involves 3 main

Segments:

1. Multi Media system
2.cluster system
3.body security system
4.Power train system

Multi Media system involves the audio devices, multimedia functionalities,

Bluetooth Connectivity, SD card functionalities etc..these things are supported using

sdars,RDS [radio digital systems], ADC[analog to digital converter] for radio's,Digital

signal processors and others.

It also Includes the navigation system [using GPS(global positioning systems)] that

displays The road map.

The input is through a HMI [human machine interface] unit that converts the

Input accordingly and displays accurate output. An MAS-K [multi audio system

Controller] is used to manage audio outputs. All these things are connected and

Embedded to a microcontroller which controls the operations.Microcontroller is also

used for basic functionalities and memory.

Cluster [or DIS (driver information systems)] system involves displaying of

Speedometers, fuel rates and various other fields of display. it has a

separate ECU for control, and in many high end cars advises optimum speed limits to

The driver and communicates with CAN. Initiates and controls climate control in a

Car, regulates AC level etc..it was analog in older generation cars, now digital.

Body security systems are those that take care of the overall security of the cars,

That includes features like antilocking facility, theft safety, airbags etc..

All these use the platform of Multicore processing, using multi thread concepts using

RTOS.

Power train system is basically used as an engine control unit that involves

functions like fuel injection,tyre pressure monitoring system, gear shifting controls

etc.

An information display system:

Fig 1:

1. Front housing with glass cover

2. Rear housing with integrated electronics and liquid-crystal display

3. Connector for the LVDS data line 4

4. Connector for the onboard power supply

Fig 2:

1 Multi-Audio System Controller

M-ASK

2 Central Information Display CID

3 Loudspeaker, front left

4 Loudspeaker, front right

5 Loudspeaker, rear left

6 Loudspeaker, rear right

7 Audio amplifiers

8 CD changer

9 Telephone control unit (e.g. Telematic Control Unit TCU)

10 GPS aerial

11 Radio aerial in the rear window

12 Connection to other control units on the KCAN, E.g. light module (dimmer)

13 Controllers

14 Instrument cluster

15 Safety and gateway module SGM

16 Dynamic stability control (DSC)

17 Steering column switch cluster SZL

Background:

The automotive industry of cars is roughly divided into three segments:

Low end segment, middle level segment, high end segments.

In a low end segment car, generally we have an analog cluster display and a

Separate audio display system that are independent of each other. There is no

Navigation systems might use an 8-bit microcontroller. Audio system has an

LCD[liquid crystal] Display.

In a mid section car, generally there is an digital cluster with basic displays, and a

separate audio display that works with a microcontroller. it has an DOT-MATRIX

display. Generally does not contain a navigation system.

In high end cars, you generally had every available option with a network connection

Between the audio and the cluster display supporting USB and BLUETOOTH

Functionalities. a 3-d TFT display interface with navigation options.

To avoid 2 different display systems MFD's came into existence, but it was only

Possible in high end cars that used a 32-bit microcontroller and a TFT display

System. Also no network was possible in middle or low end cars due to the high cost

Involved. Even in high end cars, the MFD's always were susceptible to many errors

and malfunctions due to Large chunk of data handling and high electronics involved

that also increased the cost effectiveness, which asked too much from the

Microcontroller. Also, the usage of individual hardware units and processors for each

Different section involves higher cost and unwanted complexity.

Thus there is a need for a Single robust hardware terminal with limited amount of

Electronics that can operate with a RTOS [real time operating system] in a graphical

Interface in a cost-effective manner.

A display menu:

Fig 3:

1. Display settings

2. Brightness of the Head-Up Display

3. Brightness of the Control Display (= Central Information Display)

Offset Deviation of brightness from middle position

Problem Statement:

A need for a MFD that works on a common platform, that is cost-effective

and has a single display unit.

Methodology:

In dot matrix and lcd displays, high end or 3-d graphics are very difficult to be

deciphered, hence we need every segment of cars to have a MFD that is cost-

effective, has more memory, less electronics involved and a common platform to

work upon. So here instead of a single micro-controller we take into use a SPGA

Chip [e.g. altera series] for graphical interface of nios core and a 32 bit

microcontroller. We optimize this unit in such a way that the microcontroller

synchronizes with FPGA and the whole hardware unit is hosted in a single board that

runs on an RTOS platform [specific to automotives: pro-osek, QNX]

Key Results:

Large chunk of data handling is possible in input and outputs.

2. Performance at user level - Basically displays with lot of options / animated real time screens. (Without affecting 1)

3. Low cost - For emerging markets like India, cost of these units shall be cheaper to get

(you can see the same in all markets that everyone is trying to manufacture small cars - that's paradigm shift happening).

(Without affecting 1 and 2)

4. Lower engineering turn around that involves less electronics used.

5. Threading involved in a very efficient way.

Discussion:

Due to the increase in the memory interfacing and hardware, the RAM is increased

which enhances the rate of data transmission and data load. Lot of options to choose from

and accurate real time information's mean high efficiency data displays that do not impact data transmission rate.

With Asia becoming a hub for various automakers, cost efficiency is very important.

Low cost vehicles with good display supports can greatly enhance the auto markets.

Hence these MFD's will surge the sales of every segment cars. Low electronics used,

the whole hardware component on a single board greatly reduces the engineering turn-around

that makes it highly cost effective and simple.

Scope for future work (if any):

Many Big Software firms are currently working on a technology which is a

Type of OS [operating system] that is exclusively for automotives, that uses Intel

Atom core platform on a single board. All the display details will be on one display

interface that resembles a mini laptop/notebook which uses very limited amount of

hardware reducing the number of microprocessors used, with enhanced GUI

[Graphical user interface].

Conclusion:

Thus, the future in automotive display systems is very promising and has

lots of new technologies to be unearthed using the above given possibilities

as the basic ideas. Also using above mentioned ideas we can improve and

Embed real time applications for a Multicore.