AUTOMATED DRIVING SYSTEM

Abstract

An automated driving system comprising an electronic control unit and a driver stimulation device suitable for stimulating the driver by being activated according to at least one stimulation pattern.

In this automated driving system, the electronic control unit is configured to cause said driver stimulation device to be activated according to at least one periodical stimulation pattern, when the automated driving system is activated.

Such stimulation helps the driver to maintain his or her level of situation awareness at an appropriate level at all times.

Claims

1. An automated driving system comprising an electronic control unit and a driver stimulation device suitable for stimulating a driver by being activated according to at least one stimulation pattern, wherein the electronic control unit is configured to cause said driver stimulation device to be activated according to at least one periodical stimulation pattern, when the automated driving system is activated.

2. The automated driving system according to claim 1, wherein the driver stimulation device comprises at least one stimulation signal-emitting element among a light source, a sound-emitting device, and a haptic signal-emitting device.

3. The automated driving system according to claim 1, wherein said at least one periodical stimulation pattern comprises changing an intensity and/or a colour of light, changing an intensity and/or a type of sound, and/or changing an intensity and/or a type of haptic signal.

4. The automated driving system according to claim 1, wherein the electronic control unit is configured to assess periodically a confidence level representing an assessment by the automated driving system of its own capability to drive a vehicle safely, and to cause the driver stimulation device to be activated according to at least two periodical stimulation patterns, the at least one stimulation pattern that is used being determined based at least on the confidence level.

5. The automated driving system according to claim 4, wherein the electronic control unit is configured to select a first stimulation pattern for a relatively high confidence level, and a second stimulation pattern for a lower confidence level, wherein the second stimulation pattern: a) has a frequency higher than a frequency of the first stimulation pattern; b) involves more light sources than the first stimulation pattern, the driver stimulation device comprising a plurality of light sources; c) comprises emitting at least one stronger light or noise or haptic signal to the driver, the driver stimulation device comprising respectively a light source, a sound-emitting device, or a haptic signal-emitting device; and/or d) comprises emitting light having a different colour, noise having a different frequency, and/or haptic signal having a different frequency, than respectively a colour, noise, or haptic signal of the first stimulation pattern, the driver stimulation device comprising respectively at least one light source, one sound-emitting device, and/or one haptic signal-emitting device.

6. The automated driving system according to claim 4, wherein the electronic control unit is configured, in order to determine the confidence level, to assess at least one of the following conditions: a) a speed of the vehicle exceeds a predetermined speed threshold; b) a temperature exceeds a predetermined maximum temperature threshold; c) a temperature falls below a predetermined minimum temperature threshold; d) a number of mobile elements detected by the automated driving system around the vehicle exceeds a predetermined threshold; e) at least one of sensors of the automated driving system has a failure; f) a risk of dysfunction of the automated driving system increases; g) a specific traffic behaviour is detected; h) specific weather conditions are detected; and i) a predetermined road infrastructure design is detected.

7. The automated driving system according to claim 1, wherein the electronic control unit is configured, when a confidence level is determined to be higher than a predetermined threshold, to select a first stimulation pattern having a frequency below 0.4 Hz.

8. The automated driving system according to claim 1, wherein the electronic control unit is configured, when a confidence level is determined to be higher than a predetermined threshold, to select a first stimulation pattern having a frequency below 0.2 Hz.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The present disclosure may be better understood and its numerous other objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawing wherein like reference numerals refer to like elements in the following figures and in which:

[0049] FIG. 1 is a schematic drawing in perspective of an automated driving system according to a first embodiment of the disclosure;

[0050] FIG. 2 a schematic drawing in perspective of an automated driving system according to a second embodiment of the disclosure; and

[0051] FIG. 3 is a summary table which shows how various stimulation patterns are progressively selected as a function of driving circumstances, during an exemplary trip.

DETAILED DESCRIPTION

[0052] The first embodiment will be described in relation with FIG. 1.

[0053] In the second embodiment (FIG. 2), elements identical or similar to those of the first embodiment are designated by the same reference numerals, and the description of these elements will be omitted.

[0054] In FIG. 1, the reference numeral 100 denotes a vehicle in which an automated driving system 20 is mounted.

[0055] The vehicle 100 comprises a dashboard 10, a windscreen 12, a steering wheel 14 and two pillars 16A and 16B located on the lateral sides of the windscreen 12.

[0056] The automated driving system 20 comprises an electronic control unit 25 and a driver stimulation device 30.

[0057] The electronic control unit 25 (ECU 25) is an automotive-grade control unit. It could also be formed by a plurality of control units. In some embodiments, it could possibly be located (or part of it) in a remote location, the remote elements communicating in real time with the elements aboard the vehicle.

[0058] The driver stimulation device 30 comprises several stimulation elements to stimulate the driver and keep him vigilant and aware at all times of the situation on the road. These stimulation elements are respectively a light-emitting device 32, a sound-emitting device 36, and a haptic signal-emitting device 38. All these elements are connected to the ECU 25.

[0059] The light-emitting device is formed by a stripe 32 comprising many LEDs (Light-emitting diodes), placed on the dashboard. The sound-emitting device is a loudspeaker 36 located in a radial arm of the steering wheel 14. The haptic signal emitting device 38 is formed by two vibrating plates 38A, 38B arranged in the seat bottom 52 of the driver's seat 50 (shown in dashed lines on FIGS. 1 and 2).

[0060] These locations have been been selected so that the stimulation signals be easily perceived by the driver. In particular, the location of the light-emitting device (the stripe 32) has been chosen so as to be easily perceived even when the driver performs a non-driving related task, such as looking down to operate a smartphone, or glancing to the passenger's side to discuss with a passenger, for example.

[0061] The automated driving system further comprises sensors, possibly other electronic control units, actuators, in a manner known per se (these elements are not represented). These other sensors, possible other ECUs and actuators enable the automated driving system to carry out its main function of assisting the driver.

[0062] In the present case, the automated driving system 20 is able to perform an Automated Driving function in which all controls of the car are handled automatically by the automated driving system. However, in this mode, the automated driving system 20 can sometimes require that the driver take over, in case the automated driving system 20 determines that it cannot safely drive the vehicle. Accordingly, the automated driving system 20 of the present example is a motor vehicle driving automation system classified at level 3 according to SAE norm J3016.

[0063] FIG. 2 represents an automated driving system very similar to the automated driving system represented by FIG. 1. The only difference between these two systems is the location of the light-emitting device 32. In the embodiment of FIG. 2 indeed, the light-emitting device 32 comprises two stripes 32A, 32B, each of them comprising seven LEDs (Light-emitting diodes). The LEDs are numbered 341A to 347A on the left-hand side stripe 32A, and 341B to 347B on the right-hand side stripe 32B. These LED stripes 32 replace the single LED stripe 32 of the first embodiment.

[0064] The automated driving system 20 functions as follows.

[0065] The driver stimulation device 30 is active while the Automated Driving function is active: it starts from the moment the Automated Driving function starts, by driver's demand (by pushing a specific button for example); and it terminates when the Automated Driving function stops, as actual driver's control takeover is effective (longitudinal and/or lateral control).

[0066] The stimulation provides a feedback to the driver about the Automated Driving function being on.

[0067] When the automated driving system 20 is activated, the electronic control unit 25 activates the driver stimulation device 30 according to one among four periodical stimulation patterns. The stimulation pattern which is chosen at any time depends on the confidence level determined by the automated driving system 20.

[0068] Conversely, when the automated driving is not in use, the driver stimulation system is set off, and no stimulation pattern is used: the LED stripe 32 is shut off, the loudspeaker 36 silent, the vibrating plates do not vibrate.

[0069] The four stimulation patterns consist in different stimuli, including light, sound and vibrations, as explained hereafter. These stimuli are mainly based on the visual modality, that is, on light emitted by the stripe 32 of LEDs placed on top of the vehicle's dashboard. This stripe 32 extends all along its width from the left pillar to the right pillar, as shown of FIGS. 1 and 2. The light is emitted by pulses with variable frequency. The light colour of the LEDs is also variable.

Operation

[0070] The four stimulation patterns correspond to four increasingly low confidence levels. The fourth stimulation pattern constitutes a Take-Over Request by which the automated driving system 20 requires the driver to take over.

[0071] The ECU 25 chooses the stimulation pattern based on the confidence level that it determines by detecting, understanding, and predicting the traffic situation and the trajectories of the surrounding vehicles, pedestrians and/or any other moving element(s).

[0072] In this purpose, the ECU 25 iteratively (for instance every 0.02 seconds) runs an algorithm to determine the confidence level.

[0073] The four stimulation patterns are the following:

[0074] 1. “No-event: light stimuli”: Half of the LEDs of LED stripe 32 are illuminated in white colour and blink at a 0.15 Hz pulse frequency. No sound or vibration is emitted.

[0075] This pattern is chosen when the confidence level determined by ECU 25 is below a first, high threshold A1. It is therefore usually chosen when the traffic conditions are very simple, such as on a straight road during a clear day with very good visibility, and no or few other vehicles are detected around. This pattern has a low frequency, which corresponds to breathing frequency at rest (0.15 Hz). This frequency and the colour of the LEDs are chosen to convey a neutral message to express calmness (i.e. not alerting).

[0076] 2. “High-confidence event: mild stimuli”: Half of the LEDs of LED stripe 32 are illuminated in white colour and now blink at a 0.5 Hz pulse frequency. No sound or vibration is emitted.

[0077] This pattern is chosen when the confidence level determined by ECU 25 is between the first threshold A1 and a second, intermediate threshold A2. It is therefore usually chosen when the traffic conditions are getting more complex, such as on a curve, or by the presence of some other vehicles around, for example. Since the pulse—the blinking frequency—of the LEDs is now higher, the felt “breathing rate” is relatively higher; however, the other modality characteristics (colour, noise, vibrations) are kept neutral.

[0078] The white colour and the slightly higher frequency rate of the stimuli would emulate a less relaxed breathing rate compared to the “light stimuli” (Picture 1).

[0079] 3. “Low-confidence event: strong stimuli”: All the LEDs of LED stripe 32 are now illuminated, in blue colour, and blink at a 0.5 Hz pulse frequency, and the loudspeaker 36 emits a muffled sound or beep. This beep is repeated periodically, also at a 0.5 Hz frequency. In some embodiments, the frequency of the beep itself is chosen to be rather low, such as 50 Hz. No vibration is emitted.

[0080] This pattern is chosen when the confidence level determined by ECU 25 is between the second threshold A2 and a third, low threshold A3. It is therefore usually chosen when the traffic conditions are very complex, getting close to the system's limits, such as on a curve during a rainy night with low visibility, and many other vehicles are detected around, for example. With the higher blinking frequency of the LEDs, the illumination of all LEDs rather than only five of them, the addition of the muffled sound, the higher frequency or “breathing rate” relatively high, the driver stimulation device 30 with this stimulation pattern expresses more alertness; the blue colour and the frequency rate of the stimuli emulate a more anxious and unconfident breathing rate.

[0081] 4. “Over system's limits: Take-Over Request”: All LEDs of LED stripe 32 are illuminated in red colour and blink at a 1 Hz pulse frequency, the loudspeaker 36 emits a sound which is louder than the muffled sound or beep of stimulation pattern 3, is different from that muffled sound (for instance has a frequency of 100 Hz rather than 50 Hz), and is emitted at a 1 Hz frequency (rather than 0.5 Hz); in addition, the vibrating plates 38A, 38B vibrate during vibration periods, also at a 1 Hz frequency.

[0082] This pattern is chosen when the confidence level determined by ECU 25 falls below the third threshold A3. It is therefore usually chosen when the automated driving system's limits are reached, for instance due to a sudden unexpected obstacle or event, failure of a sensor, etc. With this stimulation pattern, the stimulation frequency or “breathing rate” is further increased; the combination of signals of the pattern all tend to alert the driver and request him or her to urgently take over the control of the vehicle. The red colour and the higher frequency rate of the stimuli emulate a very anxious breathing rate. The fourth stimulation pattern constitutes a request for the driver to immediately take over.

[0083] These stimulation patterns are illustrated by FIG. 3, which represents a fictional drive by a driver, in a vehicle equipped with automated driving system 20.

[0084] During this trip, the driver initially and until time t1 does not activate the automated driving system 20. During this period, the driver stimulation device 30 remains inactive.

[0085] At time t1, the driver which has reached a highway triggers the automated driving system 20. The driver stimulation device 30 is immediately activated. The confidence level is immediately determined and found to be very high, greater than A1. The ECU 25 thus selects stimulation pattern 1, ‘No event’.

[0086] At time t2, the traffic becomes slightly denser, though being still very calm. The confidence level decreases slightly and falls below A1, though still above A2. The ECU 25 thus selects stimulation pattern 2, ‘High confidence’.

[0087] Consequently, the driver is stimulated and tends to increase his or her situation awareness.

[0088] At time t3, the traffic becomes denser, and the vehicle comes closer to a branch. The confidence level decreases and falls below A2, though still being above A3. The ECU 25 thus selects stimulation pattern 3, ‘Low confidence’. The driver is stimulated more strongly than after time t2, and tends to increase his or her situation awareness even more than after time 2.

[0089] At time t4, an animal crosses the road in front of the vehicle. The animal is detected by the automated driving system 20. The confidence level immediately falls below A3. The ECU 25 thus selects stimulation pattern 3, ‘Take-over request’ and therefore requires the driver to take over control of the vehicle in order to avoid the animal.

[0090] The four stimulation patterns presented above are of course only an exemplary embodiment of the present disclosure. Many other settings can be chosen for the stimulation patterns which can also be quite effective for maintaining the driver at an appropriate level of traffic-situation-awareness at all times. The combination of signal emitting devices (here, one or two LED stripes, a loudspeaker and two vibrating plates) can be different. In particular, it can be sufficient to include only light emitting devices, or only a combination of light-emitting device and a sound-emitting device, for instance. Also, the automated driving system can further include one of more display (including head-up display) to display more detailed information about the driving situation, the situation of the automated driving system, etc.