When car computers go wrong

Crash-test dummies

Volvo takes its safety record seriously and has been at the vanguard of new technologies geared to reducing accidents. But accidents will happen, and often at the most embarrassing moments. Twice in 2010 alone Volvo has gathered the world’s media to show off new safety features. Twice they’ve gone spectacularly wrong. The company was showing off the crash-avoidance system in its S60 when engineers fired the car out of a testing tunnel towards the back of a stationary lorry. The car was supposed to foresee the impending collision, but a problem between the control system and the battery meant the shiny new vehicle ploughed into the back of the juggernaut.

Undeterred, the company followed the S60 test with a display of a pedestrian avoidance system, which predictably ended with the simulated deaths of the walking public. Although the system, which uses radar sensors and a camera to spot pedestrians and instigate an emergency stop, did halt the vehicle for nine out of 12 dummies, three others were sent flying.

Where will it end? Well if you ask security experts, the trend for smarter cars with ever more onboard computing power means it won’t be Volvos you need to worry about, but anyone bearing a grudge.

Researchers at the University of Washington recently hacked into several car systems using a variety of attack vectors and said they could “adversarially control a wide range of automotive functions and completely ignore driver input, including disabling the brakes or selectively braking individual wheels on demand”.

Adapted from:

When computers go wrong | Analysis | Features | PC Pro

Tesla Roadster Technology and Innovations

 

The Drivetrain, Reinvented

The Roadster is powered by a 3-Phase Alternating Current Induction Motor. Small, but strong, the motor weighs just over 115 pounds. 375 volts push up to 900 Amps of current into the motor to create magnetic fields. It delivers 288 peak horsepower and 295 lbs-ft (about 400 Nm) of torque at the driver’s command. At top speed, the motor is spinning at 14,000 revolutions per minute. The motor is directly coupled to a single speed gearbox, above the rear axle. The simplicity of a single gear ratio reduces weight and eliminates the need for complicated shifting and clutch work. The elegant motor does not need a complicated reverse gear – the motor simply spins in the opposite direction. The unique design maximizes both range and acceleration.

The Industry’s best Battery

Battery Pack

The battery pack in the Tesla Roadster is the result of innovative systems engineering and 20 years of advances in Lithium-ion battery technology. The ingenious pack architecture enables world-class acceleration, safety, range, and reliability. The pack contains 6,831 lithium ion cells and is the most energy dense pack in the industry, storing 56 kWh of energy. Roadsters are engineered to charge from nearly any 120-volt or 240-volt outlet. Most Roadster owners find they rarely use a complete charge, and charging each night means their car is ready to drive 245 miles each morning.

Please visit the Tesla website as follows:

Tesla Roadster Technology and Innovations | Tesla Motors

Two-motor wiper systems

More and more carmakers are exploiting the advantages of the Bosch two-motor wiper systems. These systems, in which each of the wiper arms is driven by its own electric motor, offer the largest possible wiped area, yet are compact in construction. "The driver therefore gets the best possible view even in bad weather, and the carmaker has more space in the engine compartment for other units" is how Markus Schmidt, responsible for sales in the Energy and Body Systems Division at Bosch, explains the benefits of the system. Bosch, the world’s largest automotive supplier, began series production of the equipment in 2001. It is fitted, for instance, in the new Ford Galaxy, as well as in the recently-launched Mercedes-Benz S-Class and the Citroën C6.

In conventional wiper systems, the two arms are rigidly connected by a linkage arm, and are driven by a single motor. The Bosch two-motor wiper system synchronizes its two drives entirely electronically. Integrated sensors continuously monitor the precise position of the wiper arms. This allows the change in direction to be individually determined; the change can therefore always take place very close to the A-pillar, which provides the widest possible field of view under all conditions. Precise control of this sort is also needed, for instance, to park the wiper in the A-pillar, as is done in the Seat Altea. When the wiper is switched off, the wiper arms, together with the flat Aerotwin wiper blades, can disappear completely under the engine hood. This improves aerodynamics, and reduces the risk of injury to pedestrians and cyclists in the event of an accident. It is also possible for the wiper equipment to work fully automatically when combined with the Bosch rain and light sensors.

The wiper equipment offers real advantages to automobile manufacturers, particularly for integration into vehicles with opposed-pattern systems; it is more compact, and its two-part design means that it can be fitted very flexibly into the space available in any vehicle. Conventional systems require an awkward wiper linkage arm. Particularly in the multi-purpose vehicles that are becoming more and more popular, the Bosch wiper system helps the vehicle manufacturer make the best possible use of the tight space. Two-motor systems are therefore being used more and more often in deluxe vehicles and in both medium and compact MPV’s. "At present about five percent of all the cars manufactured in Europe are fitted with a two-motor wiper system. This proportion will double over the next five years," is Bosch expert Schmidt’s confident assessment.

www.bosch.com

Advanced Automotive Fault Diagnosis

(New book out in a few months…)

Six-stages of fault diagnosis

When a customer reports a fault here is a process to follow:

1. Verify: Is there actually a problem, confirm the symptoms

2. Collect: Get further information about the problem

3. Evaluate: Stop and think about the evidence

4. Test: Carry out further tests in a logical sequence

5. Rectify: Fix the problem

6. Check: Make sure all systems now work correctly

 

Here is a very simple example to illustrate the diagnostic process. The reported fault is excessive use of engine oil.

1. Question the customer to find out how much oil is being used (is it excessive?).

2. Examine the vehicle for oil leaks and blue smoke from the exhaust. Are there any service bulletins?

3. If leaks are found the engine could still be burning oil but leaks would be a likely cause.

4. A compression test, if the results were acceptable, would indicate a leak to be the most likely fault. Clean down the engine and run for a while. The leak will show up better.

5. Change a gasket or seal, etc.

6. Run through an inspection of the vehicle systems particularly associated with the engine. Double check the fault has been rectified and that you have not caused any further problems.

Be logical, that’s the secret!