We have been actively involved in the development of Constellation Simulator software for the multi-sensor automobile market. We have designed our own multi-function I/O (MFIO) expansion card that implements the following capabilities and data signals time-synchronized with the GPS RF output. 

The automotive system is an enhancement to our base configuration. The Multi-function I/O card is installed in a vacant card slot within the rack-mounted chassis. The user can control the error models, scaling, and personality of the combined automotive sensors. The Tapestry system generates the outputs automatically with precise synchronization with the GPS RF signal.  This is a spectacular simulation environment and has been well received by our customers, which include major European, Japanese, and US companies. We have used this system in both an engineering development and factory certification environment under remote control. Contact us for a more detailed description of this feature.

Some of the capabilities of the system include:

·        Wheel Speed pulse outputs. Four independent pulse train outputs (one from each wheel), proportional to the speed of the car, are provided. We model the inner/outer wheel separation, and effects due to wheel slip/slide. Each wheel has an independent error model consisting of bias, noise, and scale factor.  The output voltage is a 5 VDC pulse train.  The user can define the scaling up to 1.5 x 10⁶ pulses/second in either a pulse/mile or pulse/Km setting.  The output is provided on a DB25 connector on the back of the feature card.

·        Rate of Turn Analog Gyro outputs. We provide an analog 5 VDC channel simulating the output of an analog turn-rate gyro. The user may define the scaling and offset of the output voltage. For example, a typical setting is 0.025 Volts/^o/sec with a 2.50 VDC offset. This would provide a voltage output of 2.5VDC with zero applied turn rate and an approximate output of 5 / 0 VDC at a rate of ±90^o/sec. The user can control an error model that includes noise, bias, and scale factor.  We have simulated a Murata, Panasonic, and Boeing gyro with this system achieving excellent results. The output is available on a DB25 connector on the back of the feature card.

·        Analog Accelerometer outputs. A 5VDC output is provided proportional to linear acceleration. The user may define the 0-point offset and acceleration-to-voltage output from the sensor. A typical setting is 0.6 volts/G with a 0-point of 3 VDC. This system was used to simulate a ±2G sensor.  The user can control an error model simulating effects due to noise, bias, scale factor, and misalignment. The output is available on a DB25 connector on the back of the feature card.

·        Turn Table control.  A ±10VDC signal is provided that can be used to control an attached turntable. We have used the TRIO-TECH S347B model controllable via analog voltage with a dynamic range of 0.01 to 99.9 ^o/sec of rate. The rate table you select must accept an analog voltage input for the use of this feature. The output is available on a DB25 connector on the back of the feature card.

·        Reverse Motion output. A 5VDC output is provided that is brought high when the vehicle is traveling in reverse and low (0 Volts) when traveling forward. The user can reverse this logic if desired. The output is available on a DB25 connector on the back of the feature card.

·        Spare analog channel.  We have additional 5VDC analog channel that can be used for other features. They can be configured as a second accelerometer channel or used to provide a temperature-sensing signal based upon modeling. The output is available on a DB25 connector on the back of the feature card.

·        Serial Output Data.  Both COM1 and COM2 can be used to output serial automotive support data. The serial messages simulated data outputs from odometer, turn rate, and wheel speed.  We are in the process of implementing the CAN bus serial data format.

Navigation Laboratories Inc. (949) 766-0444, (949) 495-9551, Fax (949) 713-2479