| Bluetooth in Cars: | | | | To reach these goals we must have a low cost, |
| The new generations of cars will have an | | | | high performance Bluetooth unit that can be used |
| increasing number of micro controllers connected | | | | for any application. Then it has to be stripped |
| via two or more networks. An advantage of this | | | | from everything not needed by everyone, i.e., a |
| is that the car can be individually customized by | | | | concept like CAN. CAN provide the basic features |
| software, another that the car to great extent | | | | needed by any controller network, but remaining |
| can have self diagnostic functions. To fully use | | | | features required have to be provided by an |
| such features, it is necessary to have a | | | | additional higher layer protocol. The basic Bluetooth |
| bidirectional communication between the car | | | | block should take care of the RF part and the |
| system and production tools as well as service | | | | essential part of the baseband protocol that is of |
| tools for down loading new software and | | | | no or minor interest for any application but |
| parameters and uploading of status and diagnostic | | | | essential for the Bluetooth functionality. |
| messages. These production and service tool will, | | | | Communication during production: |
| to a great extent be based on pc technology. | | | | Using wireless communication between the vehicle |
| The connection between car system and the tool | | | | and the automation system of the production line |
| is made via a cable, either directly to the | | | | could open a way to completely new functions in |
| CAN(Controller Area Network) bus via a gateway. | | | | the production process. Depending on the step in |
| The cheapest way is to connect the pc directly | | | | the process, for example during final assembly, |
| to the CAN bus by drip line but this has to be | | | | the vehicle controller and controllers of the |
| short. According to the CAN standard it should be | | | | production line are able to exchange status |
| less than 39 cm at 1 Mbit/s bitrate. Compare with | | | | information both about the product and the |
| USB and Bluetooth, the mobility and versatility has | | | | process. |
| highly performed Bluetooth. | | | | Communication during service: |
| Bluetooth in car production: | | | | Potential applications during service can easily be |
| In the car production a lot of software is | | | | derived from the scenario for the production |
| downloaded as final step in the production line. | | | | process described above. Wireless communication |
| This is an application where Bluetooth would be | | | | between the vehicle and a computer of the |
| ideally suited. Bluetooth base station is connected | | | | service station can be used to exchange status |
| to the production field bus. When the car on line | | | | information and service specific information. This |
| gets connected to the Bluetooth base station, it | | | | step may be supported by a preceding data |
| uploads it serial number. The production computer | | | | exchange using telecommunication. Wireless |
| then downloads the software for this very car | | | | communication in combination with a mobile |
| via the field bus to the base station, which in turn | | | | service computer offers optimum flexibility to the |
| transmit it to the car. However, this is a dedicated | | | | service personnel. |
| use and no other Bluetooth units than those | | | | Advantages and Benefit: |
| installed in the cars should get connected to the | | | | The most important advantages of wireless |
| cell. | | | | technologies for technical tasks are more or less |
| Bluetooth for car service: | | | | hidden to the vehicle customer. The benefit of |
| A scenario for using Bluetooth could be: | | | | such a solution is the increase in flexibility, |
| 1) When the car enters the service station, its | | | | modularity and reliability. Although the benefit |
| Bluetooth station gets contact with the service | | | | cannot be experienced directly by customers it is |
| stations main computer. This has previously | | | | nonetheless important for automotive industry. |
| exchanged information with the car computer via | | | | Additionally the potential of wireless |
| the cell phone system. | | | | communication on the level of technical tasks |
| 2) The service station main computer alerts the | | | | between intelligent devices and control units inside |
| service man allotted the task and his PC | | | | the vehicle as well as control units and man |
| establishes contact with the car and downloads | | | | machine interfaces in the surrounding area of the |
| any information needed. | | | | car may lead to new functionalities and an |
| 3) The serviceman gets any work instructions | | | | increase in flexibility during production and service. |
| needed on his PC. When servicing the car, he can | | | | The benefit for the customer is an increase in |
| control and adjust several functions via the PC, | | | | reliability. For the phases of product development |
| e.g., any lights, windows, climate control, engine | | | | the increase in flexibility is a great benefit. A |
| parameters, etc. He can also download the latest | | | | simplified cable harness and wireless interfaces are |
| software versions to any Electronic Control Unit | | | | advantages for manufacturing. For service, |
| (ECU) | | | | maintenance, and repair wireless interfaces are |
| CAN/Bluetooth basics: | | | | advantageous with respect to disassembly and |
| CAN was developed to be a base for a highly | | | | assembly of parts. Additionally wireless |
| reliable communication via a twisted pair of wires | | | | communication opens possibilities for flexible |
| that could be applied from very simple tasks to | | | | connections to man machine interfaces and |
| advanced real time control. To achieve this goal, it | | | | diagnostic systems. Although in general an |
| is based on the principle that every node in a | | | | electronic component for a wireless transmission |
| system simultaneously checks each bit | | | | unit is more expensive than a cable, there are |
| transmitted on the bus. By this principle a row of | | | | several possibilities to reduce product cost, for |
| problems like buss access, collision detection, data | | | | example by standardization and by reduction of |
| consistency, etc. are solved in an elegant way. | | | | assembly efforts. |
| However, the condition that every node should | | | | Conclusion: |
| see the same bit at the same time requires a | | | | There is a potential of up to hundreds of million |
| controlled wave propagation time. This is easily | | | | per year Bluetooth nodes within the vehicle |
| achieved in a wired system but hard to achieve in | | | | manufacturer market if Bluetooth can be used for |
| a wireless system. Therefore, any wireless | | | | real time control and other technical tasks. For |
| transmissions in CAN systems have to be made | | | | several years a major trend in vehicle |
| via gateways and Bluetooth offers the best | | | | development has been the increasing number of |
| possibilities for this task among the available radio | | | | electrical and electronic systems. Many of these |
| standards. | | | | systems have been introduced to offer |
| The ideal Bluetooth concept for diagnostics: | | | | innovations to the customer by an increase in |
| The ideal Bluetooth concept for diagnostics should | | | | functionality, comfort, and safety. Another reason |
| show the following qualities: | | | | is the partial replacement of mechanical |
| 1 Low cost | | | | components by electrical components or their |
| 2 Performance as needed | | | | integration into mechatronic systems. |
| 3 Standards as needed | | | | |