Patent Description:
More recently, automated vehicle features have become possible to allow for autonomous or semi-autonomous vehicle control. For example, cruise control systems may incorporate LIDAR (light detection and ranging) for detecting an object or another vehicle in the pathway of the vehicle. Depending on the approach speed, the cruise control setting may be automatically adjusted to reduce the speed of the vehicle based on detecting another vehicle in the pathway of the vehicle.

There are different types of LIDAR systems. Flash LIDAR relies upon a single laser source to illuminate an area of interest. Reflected light from an object is detected by an avalanche photodiode array. While such systems provide useful information, the avalanche photodiode array introduces additional cost because it is a relatively expensive component. Additionally, the laser source for such systems has to be relatively high power to achieve sufficiently uniform illumination of the area of interest. Scanning LIDAR systems utilize different components compared to flash LIDAR. One challenge associated with previously proposed scanning LIDAR systems is that the scanning angle is limited. Achieving a wider field of view has required multiple MEMS mirror devices, which increases cost and requires additional packaging space. <CIT> discloses an apparatus for inspecting an optical path of an optical system. The apparatus includes a light source, typically a point light source, such as a laser and an external lens, wherein the external lens is a discrete, replaceable lens. The external lens can be inside or outside a field of view of a laser beam.

The present disclosure provides a detection device according to the independent claim. Embodiments are given in the subclaims, the description and the drawings.

An illustrative example detection device includes a source of radiation, at least one mirror that reflects radiation from the source along a field of view having a first width, at least one optic component that is configured to refract radiation reflected from the at least one mirror, and at least one actuator that selectively moves the optic component between a first position and a second position. In the first position the optic component is outside of the field of view and does not refract any of the radiation reflected from the at least one mirror. In the second position the optic component is in the field of view and refracts at least some of the radiation reflected from the at least one mirror. The field of view has a second, larger width when the at least one optic component is in the second position. The second position is variable within the field of view to achieve a plurality of second widths of the field of view.

In an example embodiment having one or more features of the detection device of the previous paragraph, the at least one optic component comprises two optic components, a first one of the two optic components is situated on a first side of the field of view, and a second one of the two optic components is situated on a second, opposite side of the field of view.

In an example embodiment having one or more features of the detection device of either of the previous paragraphs, the at least one actuator comprises a first actuator that selectively moves the first of the two optic components and a second actuator that selectively moves the second of the two optic components.

In an example embodiment having one or more features of the detection device of any of the previous paragraphs, the first actuator moves the first one of the two optic components into the second position when the second of the two optic components is in the first position and the second actuator moves the second one of the two optic components into the second position when the first of the two optic components is in the first position.

In an example embodiment having one or more features of the detection device of any of the previous paragraphs, the first and second actuator respectively move the two optic components into respective second positions and the second, larger width of the field of view includes an increase from the first width on each of the first and second sides of the field of view.

In an example embodiment having one or more features of the detection device of any of the previous paragraphs, the at least one mirror comprises a micro-electro-mechanical (MEMs) mirror.

In an example embodiment having one or more features of the detection device of any of the previous paragraphs, the radiation source comprises a laser.

In an example embodiment having one or more features of the detection device of any of the previous paragraphs, the first width of the field of view corresponds to a <NUM> degree field of view and the second width of the field of view corresponds to a <NUM> degree field of view.

In an example embodiment having one or more features of the detection device of any of the previous paragraphs, the second width is at least twice as wide as the first width.

In an example embodiment having one or more features of the detection device of any of the previous paragraphs, the optic component comprises a material having a refractive index and an anti-reflection coating having a maximum angle of incidence that establish a difference between the first and second width.

Various features and advantages of at least one disclosed example embodiment will become apparent to those skilled in the art from the following detailed description.

Embodiments of this invention provide enlarged detector field of view capability at a lower cost while occupying less space compared to other proposed arrangements. Embodiments of this invention are well-suited for automated vehicle LIDAR systems.

<FIG> schematically illustrates a vehicle <NUM> including a detection device <NUM>. One example use for the detection device <NUM> is to provide sensing or guidance information for a vehicle, engine or brake controller, such as an automated vehicle controller. For discussion purposes, the detection device <NUM> is a LIDAR device that emits at least one beam of radiation over a field of view <NUM> that is useful for detecting objects in a vicinity or pathway of the vehicle <NUM>. In this example, the beam of radiation comprises light that is directed at a selected angle relative to the vehicle <NUM>.

<FIG> schematically illustrates selected portions of the detection device <NUM> that provide the radiation along the field of view <NUM>. The detector or receiver components that provide an indication of radiation reflected from an object near the vehicle <NUM> are not shown but would be included in a manner understood by those skilled in the art. A source <NUM> of the radiation emits the radiation toward a mirror <NUM> that reflects the radiation in a desired direction. In this example, the mirror <NUM> is a micro-electro-mechanical (MEMS) mirror that operates in known manner to establish the field of view <NUM>.

Optic components <NUM> and <NUM> and associated actuators <NUM> and <NUM>, respectively, selectively change the width or scope of the field of view <NUM> by refracting at least some of the radiation reflected from the mirror <NUM>. The optic components <NUM> and <NUM> in this example comprise wedges made of an optical material having a selected index of refraction. The actuators <NUM> and <NUM> may comprise, for example, piezoelectric actuators that are capable of moving the associated optic components <NUM>, <NUM> over a range of motion across <NUM>.

<FIG> schematically shows an example technique of using the optic components <NUM> and <NUM> to selectively change the width or scope of the field of view <NUM>. In this example, the actuators <NUM> and <NUM> selectively move the respective optic components between a first position where the optic component is outside the field of view <NUM> and a second position where the optic component is at least partially within the field of view <NUM>. When at least one of the optic components <NUM>, <NUM> is in the field of view <NUM>, it refracts the radiation reflected from the mirror <NUM> in a manner that widens the field of view <NUM>.

In <FIG>, a first mode or condition is shown at <NUM> and can be considered "Mode <NUM>" in which the optic components <NUM>, <NUM> are in respective first positions and outside the field of view <NUM>. A "Mode <NUM>" is shown at <NUM> in which the actuator <NUM> moves the optic component <NUM> into a second position at least partially within the field of view <NUM> where the optic component <NUM> refracts some of the radiation to expand or widen the field of view as shown at <NUM>'. The optic component <NUM> remains in its first position in Mode <NUM>. In "Mode <NUM>" the actuator <NUM> returns the optic component <NUM> to its first position and the actuator <NUM> moves the optic component <NUM> at least partially into the field of view <NUM> to widen it as shown at <NUM>'.

<FIG> includes a timing diagram <NUM> that shows how the optic components <NUM>, <NUM> can be moved into respective first and second positions over time to achieve a desired width of the field of view <NUM>, <NUM>'. A first plot <NUM> shows the first position of the optic component <NUM> in a first position indicated by +<NUM> and the second position indicated by <NUM>. A second plot <NUM> indicates the first position of the optic component <NUM> as -<NUM> and the second position as <NUM>. Controlling the actuators <NUM> and <NUM> and sequentially moving the optic components <NUM>, <NUM> as shown in <FIG> between Modes <NUM>, <NUM> and <NUM>, provides a wider field of view <NUM>' for the detection device <NUM> during a single scanning frame.

The field of view <NUM> has a first width when both optic components <NUM>, <NUM> are in the respective first positions and the field of view <NUM>' has a second, larger width when at least one of the optic components <NUM>, <NUM> is in the respective second position. The difference between the first width and the second width may be selected to meet the needs of a particular detection device <NUM> or a particular application. For example, changing the configuration or material of the optic components will have an effect on the amount of refraction and the resulting width of the field of view. Also changing the location of the second position can alter the second width. In some embodiments, the optic components <NUM>, <NUM> are moved into about <NUM> degrees of the field of view while in others the optic components <NUM>, <NUM> are moved into about <NUM> degrees of the scanning field. Depending on the configuration of the optic components, such movement may increase the scanning field of view by as much as <NUM> or <NUM> degrees, for example.

In some embodiments the field of view <NUM> has a default range of <NUM> degrees that corresponds to the optic components <NUM>, <NUM> being in the respective first positions. When the optic components <NUM>, <NUM> are in the second position and used to achieve the wider field of view <NUM>' the scanning range or scope of the field of view is <NUM> degrees in some embodiments and <NUM> degrees in others. Other ranges are possible in some embodiments depending, for example, on the materials and configurations of the optic components. Selecting the optic component material with an appropriate refractive index and using an anti-reflection coating with a wider angle of incidence requirement makes it possible to achieve even wider ranges with acceptable transmission loss. Those skilled in the art who have the benefit of this description will realize what field of view width will best meet their particular needs and ways to select optic component features to achieve a desired width.

In <FIG>, only one of the optic components <NUM>, <NUM> moves into the second position at a particular time. Another embodiment is shown in <FIG> in which it is possible to move both optic components into the second position at the same time to achieve the wider field of view <NUM>'. Other embodiments include only one optic component instead of the two shown in the illustrated examples.

Embodiments of this invention provide a wider field of view for a detection device without requiring more than one MEMS mirror. The optic component and actuator make it possible to effectively double the range or width of the field of view at a relatively lower cost compared to increasing the number of detection devices to achieve a cumulatively larger field of view. The increased field of view available from embodiments of this invention comes at a lower cost and fits within a smaller packaging space than was otherwise possible.

Claim 1:
A detection device (<NUM>), comprising:
a source (<NUM>) of radiation;
at least one mirror (<NUM>) that reflects radiation from the source (<NUM>) along a field of view (<NUM>) having a first width;
at least one optic component (<NUM>, <NUM>) that is configured to refract radiation reflected from the at least one mirror (<NUM>); and
at least one actuator (<NUM>, <NUM>) that selectively moves the optic component (<NUM>, <NUM>) between a first position where the optic component (<NUM>, <NUM>) is outside of the field of view (<NUM>) and does not refract any of the radiation reflected from the at least one mirror (<NUM>) and a second, variable position within the field of view (<NUM>) where the optic component (<NUM>, <NUM>) refracts at least some of the radiation reflected from the at least one mirror (<NUM>), wherein the second, variable position is variable within the field of view to achieve a plurality of second widths of the field of view, wherein the field of view (<NUM>) has a second, larger width from a plurality of second widths of the field of view (<NUM>) when the at least one optic component (<NUM>, <NUM>) is in the second variable position.