Ultrasonic tracking control for an automotive vehicle

• US 5,810,105 A
• Filed: 03/13/1996
• Issued: 09/22/1998
• Est. Priority Date: 03/15/1995
• Status: Expired due to Fees

• Current Assignee: Technologietransfer-Anstalt Tetra
• Original Assignee: Technologietransfer-Anstalt Tetra
• Inventors: Trainer, Wolfram
• Primary Examiner(s): Oberleitner, Robert J.
• Assistant Examiner(s): Lee, Tyrone M.
• Application Number:
  US08/614,654
• Time in Patent Office: 923 Days
• Field of Search: 180/169, 180/167, 280/DIG. 5, 340/903, 340/904, 340/902, 340/572, 367/909, 367/6, 367/117, 367/129
• US Class Current: 180/169
• CPC Class Codes: G05D 1/0255 using acoustic signals, e.g. ultra-sonic singals sonar systems designed for anti-collision purposes G01S15/93
• CPC Class Codes: Y10S 280/05 Motorized golf carts

Abstract

The ultrasonic tracking control effects that a pacemaker going ahead is automatically tracked by an automotive vehicle at a predetermined distance. To this end, a control unit (13) of the vehicle (10) is equipped with two ultrasonic units (F1,F2) comprising a transceiver device for ultrasonic signals each. The pacemaker going ahead carries a second control unit (14) with a transponder (S) responding to the signals of the ultrasonic units (F1,F2). Upon reception of an ultrasonic signal, the transponder (S) outputs a response signal which is received by the respective ultrasonic unit. The distance of the vehicle from the pacemaker and the tracking angle (α) are determined in the first control unit (13) from the signals received by the ultrasonic units (F1,F2), and traveling and steering signals are generated such that the vehicle tracks the pacemaker at a predetermined distance.

Claims

1. An ultrasonic tracking control for a vehicle, comprising:

a first control unit (13) supplying traveling and steering signals for the traveling operation of a vehicle (10) and being arranged on the vehicle (10), and several ultrasonic units (F1, F2;

F3) of which at least two are capable of reception at different times and at least one is configured for transmission,

and a mobile second control unit (14) independent of the vehicle (10) and comprising at least one transponder (S, S1, S2) responding to the ultrasonic signals of at least one of the transmitting ultrasonic units (F1, F2;

F3),

the first control unit (13) detects the amount and direction of the distance of the vehicle (10) from the second control unit (14) by measuring the time between the emission of a signal and the reception of the response signal, and generates the traveling and steering signals such that the vehicle (10) tracks the second control unit (14) at a predetermined distance.

2. The tracking control according to claim 1, wherein the second control unit (14) includes a second transponder (S1,S2) of its own for each ultrasonic unit (F1,F2) of the first control unit (13), the pairs of ultrasonic unit and transponder being operated selectively and cross-talk-proof.

3. The tracking control according to claim 1, wherein in the first control unit one of said ultrasonic units (F₁) operates as a transmitter at a first frequency f₁ and two other ultrasonic units operate as receivers at a second frequency f₂ different from f₁, and wherein in the second control unit (14) an ultrasonic unit operates as a receiver at the frequency f₁, and a second ultrasonic unit operates as a transmitter at the frequency f₂.

4. The tracking control according to claim 3, wherein the frequencies f₁ and f₂ are each between 20 and 50 kHz.

5. The tracking control according to claim 1, wherein said ultrasonic units generate a frequency which is adjustable by the first and second control units.

6. The tracking control according to claim 1, wherein ultrasonic units (F1,F2) are controlled such that (they emit signals at non-uniform time intervals in respective active times (T1-T4), a group of active times (T1-T4) separated by non-uniform time intervals forming a repeating sequence (Q1) characteristic for the vehicle (10), and wherein the characteristic sequence (Q1) of another vehicle (A) is stored in the second control unit (14) which only responds to such signals of the first control unit (13) coinciding with the active times (T1-T4) of the sequence (Q1).

7. The tracking control according to claim 1, wherein the first control unit (13) stops the vehicle (10) if it does not receive any response signal of the transponder (S) in response to an emitted signal for a predetermined number of times within a predetermined time period.

8. The tracking control according to claim 1, wherein the second control unit (14) includes a switch so for switching off the transponder (S).

9. The tracking control according to claim 1, wherein the first control unit (13) and/or the second control unit (14) assume a waiting state with reduced energy consumption if it does not receive any signals of the other control unit over a predetermined period of time.

10. The tracking control according to claim 1, wherein the first control unit (13) evaluates new values of amount and direction of the distance of the second control unit (14) on the basis of a signal exchange with the transponder (S) only if the new values do not exceed a predetermined difference to the last valid values.

11. The tracking control according to claim 1, wherein a tracking angle (α

) of the second control unit (14) with respect to a longitudinal axis (12) of the vehicle at the predetermined distance is adjustable such that the vehicle (10) tracks the second control unit (14) with lateral offset.

12. The tracking control according to claim 1, wherein the vehicle (10) is a golf caddie with two wheels (20,21) driven by separate motors (24,25) and a self-adjusting castor wheel (22), the first control unit driving the speeds of the two motors (24,25) for steering.

13. The tracking control according to claim 12, wherein a spring device is provided which permits the castor wheel (22) to deviate from the direction suitable for straight travel only if a limit moment is exceeded.

14. The tracking control according to claim 1, wherein the first control unit (13) generating the steering signals is accommodated in a housing (26) which also carries the ultrasonic units (F1,F2,F3) and is configured as an elongated strip.

15. The tracking control according to claim 1, wherein an additional, independently acting emergency stop means is integrated in the first control unit (13), which measures the time of transmission of ultrasonic pulses from said first control unit to possible obstacles and sound pulses reflected therefrom back to the first control unit and stops the vehicle upon reception of ultrasonic pulses within a minimum transmission time.