US 5,529,138 · Granted 1996-06-25
The 1996 Laser Radar System That Saw Collisions Coming
Imagine a car that uses laser beams instead of regular radar to spot obstacles ahead and warn you before a crash. This patent describes a smart collision avoidance system that fires laser beams in a tight pattern, measures what bounces back, and calculates whether you're about to hit something—all in real time.
The plain-English version
What it protects
The claim covers a collision avoidance system using laser radars (not microwave radar) with transmitters and receivers that detect the location, direction, speed, and size of obstacles. What's protected here is the specific combination of laser radar technology paired with steering wheel rotation sensors and/or laser gyroscopes to predict collision timing, plus an optional automatic braking response when a warning is ignored. The system also protects a wheel-skidding detection method that compares predicted vs. actual directional change.
Why it matters
This patent arrived in 1996 at a moment when automotive safety was becoming a major selling point and regulatory focus. Laser radar offered superior precision compared to existing microwave radar systems—narrower beam width, better angular resolution, and stronger directionality. The combination of laser detection with automatic braking was ahead of its time; today's adaptive cruise control and collision mitigation systems trace conceptual roots to designs like this. Early adoption of this technology would have given an automaker a competitive edge in the safety category.
Real-world use
When a modern car's forward-collision warning suddenly beeps and the brakes tighten without you touching the pedal, you're experiencing descendants of this laser-based detection logic working in real time on the highway.
Original USPTO abstract
An automobile collision avoidance system based on laser radars is disclosed for aiding in avoidance of automobile collisions. The very small beam width, very small angular resolution and the highly directional character of laser radars provide a plurality of advantages as compared with microwave radars. With two sets of laser radars this system can detect the location, the direction of movement, the speed and the size of all obstacles specifically and precisely. This system includes laser radars with transmitters and receivers, a computer, a warning device and an optional automatic braking device. A steering wheel rotation sensor or a laser gyroscope is utilized to give information of system-equipped vehicle's directional change. The system will compare the predicted collision time with the minimal allowable time to determine the imminency of a collision, and when determined, provides a warning. An optional automatic braking device is disclosed to be used when the vehicle user fails to respond to a warning. Furthermore, a wheel skidding detecting system based on a discrepancy between the directional change rate predicted by a steering wheel rotation sensor and the actual directional change rate detected by a laser gyroscope is also disclosed. The detection of wheel skidding can be utilized by various vehicle control designs. An averaging device for a steering wheel and a vehicle tilting sensor are used to supplement the steering wheel rotation sensor to improve the accuracy of the automobile collision avoidance system and the wheel skidding detecting system.
Patent details
- Publication number
- US 5,529,138
- Filing date
- 1993-11-05
- Grant date
- 1996-06-25
- Assignee
- Shaw; David C. H. / Shaw; Judy Z. Z.
- Inventor(s)
- SHAW; DAVID C. H., SHAW; JUDY Z. Z.
- CPC class
- B60K23/08
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