Technical status
Description/objective
The vehicle drive-train or power-train refers to the vehicles engine, driveshaft, transmission and other components responsible for generating and delivering vehicle power to the road.
The most common system for in-vehicle data capture of the technical status of the vehicle drive-train uses microcontrollers located on individual components which can record/communicate data and perform diagnostic tests. Typically visual or auditory alarms are activated when problems occur with components and data recorded by microcontrollers can be accessed by maintenance personnel using a computer or hand-held diagnostic device via plug connectors. These are typically stand-alone devices unconnected to other systems.
Alternative systems record data from multiple components in a central on-board system where it can be accessed. Some systems are also connected to the vehicle’s on-board computer and have the capability of transmitting information to a control centre to display the current drive-train status in real time. In addition to this, some manufacturers offer devices for measuring fluid quality, vibration and corrosion fatigue. These devices can be connected to a central system for maintenance recommendation and fault classification. Where these devices are integrated with the on-board computer system performance reports can be transmitted to the maintenance department via wireless LAN while the vehicle is at a depot or station.
Applications
Primarily drive-train monitoring systems are used for operations management to monitor vehicle performance, to control maintenance schedules and to avoid unnecessary costs.
Advantages and cautions
The use of systems to detect and monitor the technical status of the vehicle drive-train provides a means of early fault detection which allows for safer and more effective running of vehicles. These systems help to minimise required maintenance and protect operations from unforeseen service disruptions due to component failures which could represent substantial costs. The provision of real-time information in some systems also enhances management control.
References
http://onlinepubs.trb.org/onlinepubs/tcrp/tcrp_rpt_43.pdf
Braking system
Description / objective
The purpose of monitoring brake system status is the same as that for monitoring any other critical vehicle component. It is to ensure safe running of vehicles, to minimise maintenance requirements and vehicle downtime and to avoid unexpected service disruptions. Modern braking systems tend to include microcontrollers which can record/communicate data, perform diagnostic tests and trigger visual and auditory alarms when faults occur. These tend to be stand alone systems with dedicated display units.
There are a number of braking system status monitoring devices currently available on the market. One such system which is intended to be retrofitted onto the existing brake unit uses sensors to monitor brake system status which are connected to a display which is mounted on the dashboard. This display provides an interface for the driver to monitor the operational status of each brake unit, indicating current status using a traffic light type warning. In addition to this, some systems are also integrated with automatic vehicle location systems to transmit data to a central location in real-time.
While the use of devices which directly monitor of the mechanical breaking system allows operators and drivers to detect and control vehicle braking performance, other devices allow for the detection and profiling of braking behaviour. Devices such as accelerometers provide this capability and are generally integrated with GPS tacking systems to provide real-time data on driver performance including braking behaviour.
Applications
- Drivers aid to indicate braking system performance and to indicate necessary maintenance.
- Operations management tool to reduce maintenance costs, vehicle downtime and unexpected service disruption.
Advantages and cautions
Early fault detection and safer vehicles running are the two primary advantages of braking system status/monitoring devices. However, these devices generally do not include the ability to profile driver behaviour. Driver braking behaviour can contribute to the level of maintenance that the braking system requires and as such it represents an area where better control could potentially reduce costs. As such, a combination of the two technologies may represent the greatest potential to minimise maintenance and achieve safer running.
References
http://onlinepubs.trb.org/onlinepubs/tcrp/tcrp_rpt_43.pdf
http://www-nrd.nhtsa.dot.gov/pdf/esv/esv21/09-0097.pdf
Tyre-pressure
Description / objective
Maintaining correct tyre pressure is a significant factor in ensuring vehicle safety and fuel efficiency and it is for this reason that tyre pressure monitoring systems have been developed. Additionally, correct tyre pressure improves handling, extends tyre life, reduces vehicle maintenance leading to less vehicle downtime and it also leads to decreased emissions levels.
There are two main types of tyre pressure monitoring systems, direct and indirect. Direct systems use sensors mounted internally or externally on the wheel to directly measure tyre pressure. Externally mounted systems are mounted on the valve stem and may be vulnerable to damage or theft, whereas internally mounted systems are mounted on the wheel hub or the inner valve stem which requires dismantling of the wheel if systems are retrofitted. Indirect systems do not use additional pressure sensors but instead use existing sensors that monitor wheel speed, such as those used in the antilock braking system, and software to calculate tyre pressure. Vibration analysis using sensors in the suspension system may also be used in combination with wheel speed data for tyre pressure calculation.
A typical example of an internally mounted direct tyre pressure monitoring system includes temperature sensor, which allows the system to compensate for pressure variations due to temperature, a pressure sensor, a signal processor, a long-life battery, a radio frequency transmitter which transmits sensor data wirelessly to a receiver and a dashboard display which allows the driver to view tyre pressure status in real-time. This dashboard mounted receiver can be shared with other car functions or dedicated to the tyre pressure monitoring system. The components mounted within the tyre make up the remote sensing unit, and sensors, battery and transmitter are managed by embedded intelligence which controls operation. The unit can also be integrated with an inertial switch to detect when the vehicle is parked to maximise battery life.
Applications
- As a driver’s aid to manage tyre pressure to maximise efficiency and handling.
- As an operations management tool to ensure safe running and to minimise maintenance requirements.
Advantages and cautions
Given that tyre pressure represents such a large contributing factor to vehicle performance, monitoring devices that ensure correct pressure at all times reduces operating costs and emissions levels. Incorrect tyre pressure also results in reduced handling performance which can and does result in accidents. As such the implementation of monitoring systems reduces the likelihood that accidents will occur.